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Java || Modulus – Celsius To Fahrenheit Conversion Displaying Degrees Divisible By 10 Using Modulus

November 20, 2012 admin No comments

This page will consist of two simple programs which demonstrate the use of the modulus operator (%).

REQUIRED KNOWLEDGE FOR THIS PROGRAM

Modulus Do/While Loop Methods (A.K.A "Functions") - What Are They? Simple Math - Divisibility Celsius to Fahrenheit Conversion

===== FINDING THE DIVISIBILITY OF A NUMBER =====

Take a simple arithmetic problem: what’s left over when you divide an odd number by an even number? The answer may not be easy to compute, but we know that it will most likely result in an answer which has a decimal remainder. How would we determine the divisibility of a number in a programming language like Java? That’s where the modulus operator comes in handy.

To have divisibility means that when you divide the first number by another number, the quotient (answer) is a whole number (i.e – no decimal values). Unlike the division operator, the modulus operator (‘%’), has the ability to give us the remainder of a given mathematical operation that results from performing integer division.

To illustrate this, here is a simple program which prompts the user to enter a number. Once the user enters a number, they are asked to enter in a divisor for the previous number. Using modulus, the program will determine if the second number is divisible by the first number. If the modulus result returns 0, the two numbers are divisible. If the modulus result does not return 0, the two numbers are not divisible. The program will keep re-prompting the user to enter in a correct choice until a correct result is obtained.





		
		
			Is It Divisible?
			
Java
			
			import java.util.Scanner;

public class Modulus
{
	// global variable declaration
	static Scanner cin = new Scanner(System.in);
	
	public static void main(String[] args)
	{
		// declare & initialize variables
		int numerator = 0;
		int denominator = 0;
		double multiple = 0;
		
		System.out.println("Welcome to My Programming Notes' Java Program.n");
		
		// get first number
		System.out.print("Please enter a value: ");
		numerator = cin.nextInt();

		// get second number
		System.out.print("nPlease enter a factor of "+numerator+": ");						

		do{ // loop will keep going until the user enters a correct answer
			
			denominator = cin.nextInt();		

			// this is the modulus declaration, which will find the 
			// remainder between the 2 numbers
			multiple = numerator % denominator;	
			
			// if the modulus result returns 0, the 2 numbers
			// are divisible
			if(multiple == 0)
			{
				System.out.println("nCorrect! "+numerator+" is divisible by "
						+denominator);
				System.out.println("n("+numerator+"/"+denominator+") = " +
						""+(numerator/denominator));
			}
			// if the user entered an incorrect choice, promt an error message
			else
			{
				System.out.print("nIncorrect, "+numerator+" is not divisible by "
					+denominator);
				System.out.print(".nnPlease enter a new multiple integer for "
						+numerator+": ");				
			}
		}while(multiple != 0);
		// ^ loop stops once user enters correct choice						
	}// end of main	
}// http://programmingnotes.org/
			
				
					
				
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						import java.util.Scanner;
 
public class Modulus
{
	// global variable declaration
	static Scanner cin = new Scanner(System.in);
	
	public static void main(String[] args)
	{
		// declare & initialize variables
		int numerator = 0;
		int denominator = 0;
		double multiple = 0;
		
		System.out.println("Welcome to My Programming Notes' Java Program.n");
		
		// get first number
		System.out.print("Please enter a value: ");
		numerator = cin.nextInt();
 
		// get second number
		System.out.print("nPlease enter a factor of "+numerator+": ");						
 
		do{ // loop will keep going until the user enters a correct answer
			
			denominator = cin.nextInt();		
 
			// this is the modulus declaration, which will find the 
			// remainder between the 2 numbers
			multiple = numerator % denominator;	
			
			// if the modulus result returns 0, the 2 numbers
			// are divisible
			if(multiple == 0)
			{
				System.out.println("nCorrect! "+numerator+" is divisible by "
						+denominator);
				System.out.println("n("+numerator+"/"+denominator+") = " +
						""+(numerator/denominator));
			}
			// if the user entered an incorrect choice, promt an error message
			else
			{
				System.out.print("nIncorrect, "+numerator+" is not divisible by "
					+denominator);
				System.out.print(".nnPlease enter a new multiple integer for "
						+numerator+": ");				
			}
		}while(multiple != 0);
		// ^ loop stops once user enters correct choice						
	}// end of main	
}// http://programmingnotes.org/

The above program determines if number ‘A’ is divisible be number ‘B’ via modulus. Unlike the division operator, which does not return the remainder of a number, the modulus operator does, thus we are able to find divisibility between two numbers.

To demonstrate the above code, here is a sample run:

Welcome to My Programming Notes' Java Program.
Please enter a value: 21 Please enter a factor of 21: 5 Incorrect, 21 is not divisible by 5. Please enter a new multiple integer for 21: 7 Correct! 21 is divisible by 7
(21/7) = 3

===== CELSIUS TO FAHRENHEIT CONVERSION DISPLAYING DEGREES DIVISIBLE BY 10 =====

Now that we understand how modulus works, the second program shouldn’t be too difficult. This function first prompts the user to enter in an initial (low) value. After the program obtains the low value from the user, the program will ask for another (high) value. After it obtains the needed information, it displays all the degrees, from the range of the low number to the high number, which are divisible by 10. So if the user enters a low value of 3 and a high value of 303, the program will display all of the Celsius to Fahrenheit degrees within that range which are divisible by 10.





		
		
			Celsius To Fahrenheit Conversion
			
Java
			
			import java.util.Scanner;

public class Temperature
{
	// global variable declaration
	static Scanner cin = new Scanner(System.in);
	
	public static void main(String[] args)
	{
		// declare & initialize variables
		int low = 0;
		int high = 0;
		double degreeFahrenhiet = 0;
		double multiple = 0;
		
		System.out.println("Welcome to My Programming Notes' Java Program.n");	
		
		// get data from user
		System.out.print("Enter a low number: ");
		low = cin.nextInt();

		System.out.print("nEnter a high number: ");
		high = cin.nextInt();
		
		// displays data back to user in table form
		System.out.print("nCelsius Fahrenheit:n");
		
		// display the initial 'low' converted degrees to the user
		System.out.println(low+"t"+ConvertCelsiusToFahrenheit(low));	
		
		// this loop displays all the degrees that are divisible by 10
		do{ 
			// this increments the current degree number by 1
			++low;
			
			// this converts the current number from celsius to fahrenhiet
			degreeFahrenhiet = ConvertCelsiusToFahrenheit(low);

			// this is the modulus operation which finds the 
			// numbers which are divisible by 10
			multiple = low % 10;		

			// the program will only display the degrees to the user via
			// cout which are divisible by 10
			if(multiple == 0)
			{
				System.out.println(low+"t"+degreeFahrenhiet);
			}			
		}while(low < high);
		// ^ loop stops once the 'low' variable reaches the 'high' variable	
		
		// displays the 'high' converted degrees to the user
		System.out.println(high+"t"+ConvertCelsiusToFahrenheit(high));		
	}// end of main	
	
	static double ConvertCelsiusToFahrenheit(int degree)
	{
		return ((1.8 * degree) + 32.0);
	}// end of ConvertCelsiusToFahrenheit
}// http://programmingnotes.org/
			
				
					
				
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						import java.util.Scanner;
 
public class Temperature
{
	// global variable declaration
	static Scanner cin = new Scanner(System.in);
	
	public static void main(String[] args)
	{
		// declare & initialize variables
		int low = 0;
		int high = 0;
		double degreeFahrenhiet = 0;
		double multiple = 0;
		
		System.out.println("Welcome to My Programming Notes' Java Program.n");	
		
		// get data from user
		System.out.print("Enter a low number: ");
		low = cin.nextInt();
 
		System.out.print("nEnter a high number: ");
		high = cin.nextInt();
		
		// displays data back to user in table form
		System.out.print("nCelsius Fahrenheit:n");
		
		// display the initial 'low' converted degrees to the user
		System.out.println(low+"t"+ConvertCelsiusToFahrenheit(low));	
		
		// this loop displays all the degrees that are divisible by 10
		do{ 
			// this increments the current degree number by 1
			++low;
			
			// this converts the current number from celsius to fahrenhiet
			degreeFahrenhiet = ConvertCelsiusToFahrenheit(low);
 
			// this is the modulus operation which finds the 
			// numbers which are divisible by 10
			multiple = low % 10;		
 
			// the program will only display the degrees to the user via
			// cout which are divisible by 10
			if(multiple == 0)
			{
				System.out.println(low+"t"+degreeFahrenhiet);
			}			
		}while(low < high);
		// ^ loop stops once the 'low' variable reaches the 'high' variable	
		
		// displays the 'high' converted degrees to the user
		System.out.println(high+"t"+ConvertCelsiusToFahrenheit(high));		
	}// end of main	
	
	static double ConvertCelsiusToFahrenheit(int degree)
	{
		return ((1.8 * degree) + 32.0);
	}// end of ConvertCelsiusToFahrenheit
}// http://programmingnotes.org/

QUICK NOTES:
The highlighted lines are sections of interest to look out for.

The code is heavily commented, so no further insight is necessary. If you have any questions, feel free to leave a comment below.

Once compiled, you should get this as your output

Welcome to My Programming Notes' Java Program.
Enter a low number: 3 Enter a high number: 303
Celsius Fahrenheit: 3..........37.4 10.........50 20.........68 30.........86 40........104 50........122 60........140 70........158 80........176 90........194 100.......212 110.......230 120.......248 130.......266 140.......284 150.......302 160.......320 170.......338 180.......356 190.......374 200.......392 210.......410 220.......428 230.......446 240.......464 250.......482 260.......500 270.......518 280.......536 290.......554 300.......572 303.......577.4

Java || Random Number Guessing Game Using Random & Do/While Loop

November 19, 2012 admin No comments

This is a simple guessing game, which demonstrates the use of the “Random” class to generate random numbers. This program first prompts the user to enter a number between 1 and 1000. Using if/else statements, the program will check to see if the user obtained number is higher/lower than the pre defined random number which is generated by the program. If the user makes a wrong guess, the program will re prompt the user to enter in a new number, where they will have a chance to enter in a new guess. Once the user finally guesses the correct answer, using a do/while loop, the program will ask if they want to play again. If the user selects yes, the game will start over, and a new random number will be generated. If the user selects no, the game will end.

REQUIRED KNOWLEDGE FOR THIS PROGRAM

The "Random" Class Do/While Loop How To get Character Input Custom Setw/Setfill In Java





		
		
			I'm Thinking of a Number Between 1 and 1000...
			
Java
			
			// ============================================================================
//    Author: Kenneth Perkins
//    Date:   Nov 19, 2012
//    Taken From: http://programmingnotes.org/
//    File:  GuessingGame.java
//    Description: Demonstrates a simple random number guessing game
// ============================================================================
import java.util.*;

public class GuessingGame
{
    // global variable declarations
    static Scanner cin = new Scanner(System.in);
    static Random rand = new Random(); // this is the call to the "Random" class

    public static void main(String[] args)
    {
        // declare & initialize variables
        char playAgain = 'y';
        int userInput = 0;
        int numGuesses = 0;
        int randomNumber = rand.nextInt(1000)+1;
        // ^ get a number from the random generator in the range of 1 - 1000

        System.out.println("Welcome to My Programming Notes' Java Program.\n");

        // display directions to user
        System.out.println("I'm thinking of a number between 1 and 1000. Go " +
                "ahead and make your first guess.\n");

        do { // this is the start of the do/while loop

            System.out.print(">> ");
            // get data from user
            userInput = cin.nextInt();
            System.out.println("");

            // increments the 'numGuesses' variable each time the user
            // gets the guess wrong
            ++numGuesses;

            // if user guess is too high, do this code
            if (userInput > randomNumber)
            {
                System.out.println("Too high! Think lower.");
            }

            // if user guess is too low, do this code
            else if (userInput < randomNumber)
            {
                System.out.println("Too low! Think higher.");
            }

            // if user guess is correct, do this code
            else
            {    // display data to user, prompt if user wants to play again
                System.out.print("You got it, and it only took you "
                    +numGuesses+" trys!\nWould you like to play again (y/n)? ");
                playAgain = cin.next().charAt(0);

                // if user wants to play again then re initialize the variables
                if (playAgain == 'y'|| playAgain == 'Y')
                {
                    // creates a line seperator if user wants to enter new data
                    System.out.println("");
                    setwRF("", 60, '-');

                    numGuesses = 0;
                    System.out.println("\n\nMake a guess (between 1-1000):\n");
                    // generate a new random number for the user to try & guess
                    randomNumber = rand.nextInt(1000)+1;
                }
            }
            System.out.println("");
        } while (playAgain == 'y' || playAgain == 'Y');
        // ^ do/while loop ends when user doesnt select 'Y'
        // display data to user
        System.out.println("Thanks for playing!!");
    }// end of main

    public static void setwRF(String str, int width, char fill)
    {
        System.out.print(str);
        for (int x = str.length(); x < width; ++x)
        {
            System.out.print(fill);
        }
    }// end of setwRF
}// http://programmingnotes.org/
			
				
					
				
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						// ============================================================================
//    Author: Kenneth Perkins
//    Date:   Nov 19, 2012
//    Taken From: http://programmingnotes.org/
//    File:  GuessingGame.java
//    Description: Demonstrates a simple random number guessing game
// ============================================================================
import java.util.*;
 
public class GuessingGame
{
    // global variable declarations
    static Scanner cin = new Scanner(System.in);
    static Random rand = new Random(); // this is the call to the "Random" class
 
    public static void main(String[] args)
    {
        // declare & initialize variables
        char playAgain = 'y';
        int userInput = 0;
        int numGuesses = 0;
        int randomNumber = rand.nextInt(1000)+1;
        // ^ get a number from the random generator in the range of 1 - 1000
 
        System.out.println("Welcome to My Programming Notes' Java Program.\n");
 
        // display directions to user
        System.out.println("I'm thinking of a number between 1 and 1000. Go " +
                "ahead and make your first guess.\n");
 
        do { // this is the start of the do/while loop
 
            System.out.print(">> ");
            // get data from user
            userInput = cin.nextInt();
            System.out.println("");
 
            // increments the 'numGuesses' variable each time the user
            // gets the guess wrong
            ++numGuesses;
 
            // if user guess is too high, do this code
            if (userInput > randomNumber)
            {
                System.out.println("Too high! Think lower.");
            }
 
            // if user guess is too low, do this code
            else if (userInput < randomNumber)
            {
                System.out.println("Too low! Think higher.");
            }
 
            // if user guess is correct, do this code
            else
            {    // display data to user, prompt if user wants to play again
                System.out.print("You got it, and it only took you "
                    +numGuesses+" trys!\nWould you like to play again (y/n)? ");
                playAgain = cin.next().charAt(0);
 
                // if user wants to play again then re initialize the variables
                if (playAgain == 'y'|| playAgain == 'Y')
                {
                    // creates a line seperator if user wants to enter new data
                    System.out.println("");
                    setwRF("", 60, '-');
 
                    numGuesses = 0;
                    System.out.println("\n\nMake a guess (between 1-1000):\n");
                    // generate a new random number for the user to try & guess
                    randomNumber = rand.nextInt(1000)+1;
                }
            }
            System.out.println("");
        } while (playAgain == 'y' || playAgain == 'Y');
        // ^ do/while loop ends when user doesnt select 'Y'
        // display data to user
        System.out.println("Thanks for playing!!");
    }// end of main
 
    public static void setwRF(String str, int width, char fill)
    {
        System.out.print(str);
        for (int x = str.length(); x < width; ++x)
        {
            System.out.print(fill);
        }
    }// end of setwRF
}// http://programmingnotes.org/

QUICK NOTES:
The highlighted lines are sections of interest to look out for.

The code is heavily commented, so no further insight is necessary. If you have any questions, feel free to leave a comment below.

Once compiled, you should get this as your output:

Welcome to My Programming Notes' Java Program.
I'm thinking of a number between 1 and 1000. Go ahead and make your first guess. >> 900 Too high! Think lower. >> 300 Too high! Think lower. >> 100 Too low! Think higher. >> 200 Too low! Think higher. >> 350 You got it, and it only took you 5 trys! Would you like to play again (y/n)? y ------------------------------------------------------------ Make a guess (between 1-1000): >> 300 Too low! Think higher. >> 600 Too high! Think lower. >> 500 Too high! Think lower. >> 400 You got it, and it only took you 4 trys! Would you like to play again (y/n)? n
Thanks for playing!!

C++ || Char Array – Palindrome Number Checker Using A Character Array, Strlen, Strcpy, & Strcmp

July 10, 2012 admin No comments

The following is a palindromic number checking program, which demonstrates more use of character array’s, Strlen, & Strcmp.

Want sample code for a palindrome checker which works for numbers and words? Click here.

REQUIRED KNOWLEDGE FOR THIS PROGRAM

Character Arrays How to reverse a character array Palindrome - What is it? Strlen Strcpy Strcmp Isdigit Atoi - Convert a char array to a number Do/While Loops For Loops

This program first asks the user to enter a number that they wish to compare for similarity. If the number which was entered into the system is a palindrome, the program will prompt a message to the user via cout. This program determines similarity by using the strcmp function to compare two arrays together. Using a for loop, this program also demonstrates how to reverse a character array, aswell as demonstrates how to determine if the text contained in a character array is a number or not.

This program will repeatedly prompt the user for input until an “exit code” is obtained. The designated exit code in this program is the number 0 (zero). So the program will not stop asking for user input until the number 0 is entered into the program.





		
		
			Palindrome Number Checker Using A Char Array
			
C++
			
			// ============================================================================
//    Author: Kenneth Perkins
//    Date:   Jul 10, 2012
//    Taken From: http://programmingnotes.org/
//    File:  palindrome.cpp
//    Description: Palindrome number checker
// ============================================================================
#include <iostream>
#include <cctype>
#include <cstring>
#include <cstdlib>
using namespace std;

// function prototypes
void Reverse(char arry[]);
bool IsArryANum(char arry[]);

// constant, which is the exit value 
const char* EXIT_VALUE = "0";

int main()
{
    // declare variables
    char arry[80];
    char arryReversed[80];
    
    do{// get data from user using do/while loop
        cout<<"\nEnter a positive integer, or ("<<EXIT_VALUE<<") to exit: ";
        
        cin >> arry;
        
        if(atoi(arry) < 0) // check for negative numbers
        {
            cout <<"\n*** Error: "<<arry<<" must be greater than zero\n";
        }
        else if(!IsArryANum(arry)) // check for any letters 
        {
            cout <<"\n*** Error: "<<arry<<" is not an integer\n";
        }
        else if(strcmp(EXIT_VALUE, arry) == 0) // check for "exit code"
        {
            cout <<"\nExiting program...\n";
        }
        else // if all else is good, determine if number is a palindrome 
        {
            // copy the user input from the first array (arry)
            // into the second array (arryReversed)
            strcpy(arryReversed, arry);

            // function call to reverse the contents inside the
            // "arryReversed" array to check for similarity
            Reverse(arryReversed);
            
            cout <<endl<<arry;

            // use strcmp to determine if the two arrays are the same
            if(strcmp(arryReversed, arry) == 0)
            {
                cout <<" is a Palindrome..\n";
            }
            else
            {
                cout <<" is NOT a Palindrome!\n";
            }
        }
    }while(strcmp(EXIT_VALUE, arry) != 0); // keep going until user enters the exit value

    cout <<"\nBYE!\n";
    
    return 0;
}// end of main

void Reverse(char arry[])
{
    // get the length of the current word in the array index
    int length = strlen(arry)-1;
    
    // increment thru each letter within the current char array index
    // reversing the order of the array
    for (int currentChar=0; currentChar < length; --length, ++currentChar)
    {
        // copy 1st letter in the array index into temp
        char temp = arry[currentChar];
        // copy last letter in the array index into the 1st array index
        arry[currentChar] = arry[length];
        // copy temp into last array index
        arry[length] = temp;
    }
}// end of Reverse

bool IsArryANum(char arry[])
{
    // LOOP UNTIL U REACH THE NULL CHARACTER,
    // AKA THE END OF THE CHAR ARRAY
    for(int x=0; arry[x]!='\0'; ++x)
    {               
        // if the current char isnt a number,
        // exit the loop & return false
        if(!isdigit(arry[x])) 
        {
            return false;
        }
    }
    return true;
}// http://programmingnotes.org/
			
				
					
				
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						// ============================================================================
//    Author: Kenneth Perkins
//    Date:   Jul 10, 2012
//    Taken From: http://programmingnotes.org/
//    File:  palindrome.cpp
//    Description: Palindrome number checker
// ============================================================================
#include <iostream>
#include <cctype>
#include <cstring>
#include <cstdlib>
using namespace std;
 
// function prototypes
void Reverse(char arry[]);
bool IsArryANum(char arry[]);
 
// constant, which is the exit value 
const char* EXIT_VALUE = "0";
 
int main()
{
    // declare variables
    char arry[80];
    char arryReversed[80];
    
    do{// get data from user using do/while loop
        cout<<"\nEnter a positive integer, or ("<<EXIT_VALUE<<") to exit: ";
        
        cin >> arry;
        
        if(atoi(arry) < 0) // check for negative numbers
        {
            cout <<"\n*** Error: "<<arry<<" must be greater than zero\n";
        }
        else if(!IsArryANum(arry)) // check for any letters 
        {
            cout <<"\n*** Error: "<<arry<<" is not an integer\n";
        }
        else if(strcmp(EXIT_VALUE, arry) == 0) // check for "exit code"
        {
            cout <<"\nExiting program...\n";
        }
        else // if all else is good, determine if number is a palindrome 
        {
            // copy the user input from the first array (arry)
            // into the second array (arryReversed)
            strcpy(arryReversed, arry);
 
            // function call to reverse the contents inside the
            // "arryReversed" array to check for similarity
            Reverse(arryReversed);
            
            cout <<endl<<arry;
 
            // use strcmp to determine if the two arrays are the same
            if(strcmp(arryReversed, arry) == 0)
            {
                cout <<" is a Palindrome..\n";
            }
            else
            {
                cout <<" is NOT a Palindrome!\n";
            }
        }
    }while(strcmp(EXIT_VALUE, arry) != 0); // keep going until user enters the exit value
 
    cout <<"\nBYE!\n";
    
    return 0;
}// end of main
 
void Reverse(char arry[])
{
    // get the length of the current word in the array index
    int length = strlen(arry)-1;
    
    // increment thru each letter within the current char array index
    // reversing the order of the array
    for (int currentChar=0; currentChar < length; --length, ++currentChar)
    {
        // copy 1st letter in the array index into temp
        char temp = arry[currentChar];
        // copy last letter in the array index into the 1st array index
        arry[currentChar] = arry[length];
        // copy temp into last array index
        arry[length] = temp;
    }
}// end of Reverse
 
bool IsArryANum(char arry[])
{
    // LOOP UNTIL U REACH THE NULL CHARACTER,
    // AKA THE END OF THE CHAR ARRAY
    for(int x=0; arry[x]!='\0'; ++x)
    {               
        // if the current char isnt a number,
        // exit the loop & return false
        if(!isdigit(arry[x])) 
        {
            return false;
        }
    }
    return true;
}// http://programmingnotes.org/

QUICK NOTES:
The highlighted lines are sections of interest to look out for.

The code is heavily commented, so no further insight is necessary. If you have any questions, feel free to leave a comment below.

Once compiled, you should get this as your output

Enter a positive integer, or (0) to exit: L33T
*** error: "L33T" is not an integer Enter a positive integer, or (0) to exit: -728 *** error: -728 must be greater than zero Enter a positive integer, or (0) to exit: 1858 1858 is NOT a Palindrome! Enter a positive integer, or (0) to exit: 7337 7337 is a Palindrome.. Enter a positive integer, or (0) to exit: 0 Exiting program...
BYE!

Java || Find The Prime, Perfect & All Known Divisors Of A Number Using A For, While & Do/While Loop

June 24, 2012 admin No comments

This program was designed to better understand how to use different loops which are available in Java, as well as more practice using objects with classes.

This program first asks the user to enter a non negative number. After it obtains a non negative integer from the user, the program determines if the user obtained number is a prime number or not, aswell as determining if the user obtained number is a perfect number or not. After it obtains its results, the program will display to the screen if the user inputted number is prime/perfect number or not. The program will also display a list of all the possible divisors of the user obtained number via stdout.

REQUIRED KNOWLEDGE FOR THIS PROGRAM

Class Objects - How TO Use Constructors - What Are They? Do/While Loop While Loop For Loop Modulus Basic Math - Prime Numbers Basic Math - Perfect Numbers Basic Math - Divisors





		
		
			Is It Prime or Perfect? List All Possible Divisors
			
Java
			
			import java.util.Scanner;

public class PrimePerfectNums
{
	// global variable declaration
	int userInput = 0;	
	static Scanner cin = new Scanner(System.in);
	
	public PrimePerfectNums(int input)
	{// this is the constructor
		// give the global variable a value
		userInput = input;

	}// end of PrimePerfectNums
	
	public void CalcPrimePerfect() 
	{
		// declare variables
		int divisor = 0;
		int sumOfDivisors = 0;		
		
		System.out.print("nInput number: " + userInput);
		
		// for loop adds sum of all possible divisors
		for(int counter=1; counter <= userInput; ++counter)
		{
			divisor = (userInput % counter);
			if(divisor == 0)
			{
				// this will repeatedly add the found divisors together
				sumOfDivisors += counter;
			}
		}
		
		System.out.println("");
		// uses the 'sumOfDivisors' variable from ^ above for loop to
		// check if 'userInput' is prime
		if(userInput == (sumOfDivisors - 1))
		{
			System.out.print(userInput + " is a prime number.");
		}
		else
		{
			System.out.print(userInput + " is not a prime number.");
		}
		
		System.out.println("");
		// uses the 'sumOfDivisors' variable from ^ above for loop to
		// check if 'userInput' is a perfect number
		if (userInput == (sumOfDivisors - userInput))
		{
			System.out.print(userInput + " is a perfect number.");
		}
		else
		{
			System.out.print(userInput + " is not a perfect number.");
		}
		
		System.out.print("nDivisors of " + userInput + " are: ");
		// for loop lists all the possible divisors for the
		// 'userInput' variable by using the modulus operator
		for(int counter=1; counter <= userInput; ++counter)
		{
			divisor = (userInput % counter);
			if(divisor == 0 && counter !=userInput)
			{
				System.out.print(counter + ", ");
			}
		}
		
		System.out.print("and " + userInput);					
	}// end of CalcPrimePerfect
	
	public static void main(String[] args)
	{
		// declare variables
		int input = 0;
		char response ='n';
		
		do{ // this is the start of the do/while loop
			
			System.out.print("Enter a number: ");
			input = cin.nextInt();
			
			// if the user inputs a negative number, do this code
			while(input < 0) 
			{
				System.out.print("ntSorry, but the number entered is less " +
						"than the allowable limit.ntPlease try again.....");
				System.out.print("nnEnter an number: ");
				input = cin.nextInt();
			}
			// entry point to class declaration
			PrimePerfectNums myClass = new PrimePerfectNums(input);
			
			// function call to obtain data using the number
			// which was passed from main to the constructor
			myClass.CalcPrimePerfect();
			
			// asks user if they want to enter new data
			System.out.print("nntDo you want to input another number?(Y/N): ");
			response = cin.next().toLowerCase().charAt(0);
			
			System.out.println("---------------------------" +
				"---------------------------------");		
		}while(response =='y');
		// ^ End of the do/while loop. As long as the user chooses
		// 'Y' the loop will keep going.
		// It stops when the user chooses the letter 'N'
		
		System.out.println("BYE!");		
	}// end of main	
}// http://programmingnotes.org/
			
				
					
				
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						import java.util.Scanner;
 
public class PrimePerfectNums
{
	// global variable declaration
	int userInput = 0;	
	static Scanner cin = new Scanner(System.in);
	
	public PrimePerfectNums(int input)
	{// this is the constructor
		// give the global variable a value
		userInput = input;
 
	}// end of PrimePerfectNums
	
	public void CalcPrimePerfect() 
	{
		// declare variables
		int divisor = 0;
		int sumOfDivisors = 0;		
		
		System.out.print("nInput number: " + userInput);
		
		// for loop adds sum of all possible divisors
		for(int counter=1; counter <= userInput; ++counter)
		{
			divisor = (userInput % counter);
			if(divisor == 0)
			{
				// this will repeatedly add the found divisors together
				sumOfDivisors += counter;
			}
		}
		
		System.out.println("");
		// uses the 'sumOfDivisors' variable from ^ above for loop to
		// check if 'userInput' is prime
		if(userInput == (sumOfDivisors - 1))
		{
			System.out.print(userInput + " is a prime number.");
		}
		else
		{
			System.out.print(userInput + " is not a prime number.");
		}
		
		System.out.println("");
		// uses the 'sumOfDivisors' variable from ^ above for loop to
		// check if 'userInput' is a perfect number
		if (userInput == (sumOfDivisors - userInput))
		{
			System.out.print(userInput + " is a perfect number.");
		}
		else
		{
			System.out.print(userInput + " is not a perfect number.");
		}
		
		System.out.print("nDivisors of " + userInput + " are: ");
		// for loop lists all the possible divisors for the
		// 'userInput' variable by using the modulus operator
		for(int counter=1; counter <= userInput; ++counter)
		{
			divisor = (userInput % counter);
			if(divisor == 0 && counter !=userInput)
			{
				System.out.print(counter + ", ");
			}
		}
		
		System.out.print("and " + userInput);					
	}// end of CalcPrimePerfect
	
	public static void main(String[] args)
	{
		// declare variables
		int input = 0;
		char response ='n';
		
		do{ // this is the start of the do/while loop
			
			System.out.print("Enter a number: ");
			input = cin.nextInt();
			
			// if the user inputs a negative number, do this code
			while(input < 0) 
			{
				System.out.print("ntSorry, but the number entered is less " +
						"than the allowable limit.ntPlease try again.....");
				System.out.print("nnEnter an number: ");
				input = cin.nextInt();
			}
			// entry point to class declaration
			PrimePerfectNums myClass = new PrimePerfectNums(input);
			
			// function call to obtain data using the number
			// which was passed from main to the constructor
			myClass.CalcPrimePerfect();
			
			// asks user if they want to enter new data
			System.out.print("nntDo you want to input another number?(Y/N): ");
			response = cin.next().toLowerCase().charAt(0);
			
			System.out.println("---------------------------" +
				"---------------------------------");		
		}while(response =='y');
		// ^ End of the do/while loop. As long as the user chooses
		// 'Y' the loop will keep going.
		// It stops when the user chooses the letter 'N'
		
		System.out.println("BYE!");		
	}// end of main	
}// http://programmingnotes.org/

QUICK NOTES:
The highlighted lines are sections of interest to look out for.

The code is heavily commented, so no further insight is necessary. If you have any questions, feel free to leave a comment below.

Once compiled, you should get this as your output:

Enter a number: 41
Input number: 41 41 is a prime number. 41 is not a perfect number. Divisors of 41 are: 1, and 41 Do you want to input another number?(Y/N): y ------------------------------------------------------------ Enter a number: 496 Input number: 496 496 is not a prime number. 496 is a perfect number. Divisors of 496 are: 1, 2, 4, 8, 16, 31, 62, 124, 248, and 496 Do you want to input another number?(Y/N): y ------------------------------------------------------------ Enter a number: 1858 Input number: 1858 1858 is not a prime number. 1858 is not a perfect number. Divisors of 1858 are: 1, 2, 929, and 1858 Do you want to input another number?(Y/N): y ------------------------------------------------------------ Enter a number: -9 Sorry, but the number entered is less than the allowable limit. Please try again..... Enter an number: 12 Input number: 12 12 is not a prime number. 12 is not a perfect number. Divisors of 12 are: 1, 2, 3, 4, 6, and 12
Do you want to input another number?(Y/N): n ------------------------------------------------------------ BYE!

Java || Compute The Sum From A String Of Integers & Display Each Number Individually

June 03, 2012 admin No comments

Here is a simple program, which was presented in a Java course. This program was used to introduce the input/output mechanisms which are available in Java. This assignment was modeled after Exercise 2.30, taken from the textbook “Java How to Program” (early objects) (9th Edition) (Deitel). It is the same exercise in both the 8th and 9th editions.

Our class was asked to make a program which prompts the user to enter a non-negative integer into the system. The program was supposed to then extract the digits from the inputted number, displaying them each individually, separated by a white space (” “). After the digits are displayed, the program was then supposed to display the sum of those digits to the screen. So for example, if the user inputted the number “39465,” the program would output the numbers 3 9 4 6 5 individually, and then the sum of 27.

REQUIRED KNOWLEDGE FOR THIS PROGRAM

How To Get String Input If/Else Statements Do/While Loops For Loops Methods (A.K.A "Functions") - What Are They? ParseInt - Convert String To Integer Substring Try/Catch





		
		
			Compute The Sum From A String Of Numbers
			
Java
			
			import java.util.Scanner;
import java.lang.Math;

public class SumFromString
{
   public static void main(String[] args)
   {
	   // declare variables
	   char question = 'n';
	   String userInput= " ";
	   Scanner cin = new Scanner(System.in);
	   
	   // display message to screen
	   System.out.println("nWelcome to My Programming Notes' Java Program.");
	   
	   do{// this is the start of the do/while loop	   
		   int sum = 0;
		   
		   // get data from the user
		   System.out.print("nEnter a non negative integer: ");
		   userInput = cin.nextLine();
		   
		   System.out.println("");
		   
		   // if the string isnt a number, dont compute the sum
		   if(!IsNumeric(userInput))
		   {
			   System.out.println(userInput+" is not a number...");
			   System.out.println("Please enter digits only!");	
		   }
		   
		   // if the string is a negative number, dont compute the sum
		   else if(IsNegative(userInput))
		   {
			   System.out.println(userInput+" is a negative number...");
			   System.out.println("Please enter positive digits only!");
		   }
		   
		   // if the string is a decimal number (i.e 19.87), dont compute the sum
		   else if(IsDecimal(userInput))
		   {
			   System.out.println(userInput+" is a decimal number...");
			   System.out.println("Please enter positive whole numbers only!");		  		
		   }
		   
		   // if everything else checks out OK, then compute the sum
		   else
		   {
			   System.out.print("The digits are: ");
			   sum = ComputeSum(userInput); 
			   System.out.println("and the sum is " + sum);
		   }
		   
		   // ask user if they want to enter more data
		   System.out.print("nDo you have more data for input? (Y/N): ");
		   String response = cin.nextLine();
		   response=response.toLowerCase();
		   question = response.charAt(0);
		   
		   System.out.println("n------------------------------------------------");
		   
	   }while(question == 'y');
	   
	   System.out.print("nBYE!n");
   }// end of main
   
   public static boolean IsNumeric(String str)  
   {// checks to see if a string is a number  
	   try
	   { 
		   Double.parseDouble(str);
		   return true;		   
	   }
	   catch(NumberFormatException nfe)
	   { 
		   return false;
	   }
   }// end of IsNumeric
   
   public static boolean IsNegative(String str)  
   {// checks to see if string is a negative number  
	   return Double.parseDouble(str) < 0;
   }// end of IsNegative   
   
   public static boolean IsDecimal(String str)  
   {// checks to see if string is a decimal number  
	   return (Math.floor(Double.parseDouble(str))) != Double.parseDouble(str);
   }// end of IsDecimal
   
   public static int ComputeSum(String userInput)
   {// displays each number individually & computes the sum of the string 
	   int sum = 0;
	   String[] temp = new String[userInput.length()];
	   
	   for(int counter=0; counter < userInput.length(); ++counter)
	   {
		   temp[counter] = userInput.substring(counter,counter+1); 
		   System.out.print(temp[counter] + " ");
		   sum = sum + Integer.parseInt(temp[counter]);
	   }
	   return sum;
   }// end of ComputeSum
}// http://programmingnotes.org/
			
				
					
				
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						import java.util.Scanner;
import java.lang.Math;
 
public class SumFromString
{
   public static void main(String[] args)
   {
	   // declare variables
	   char question = 'n';
	   String userInput= " ";
	   Scanner cin = new Scanner(System.in);
	   
	   // display message to screen
	   System.out.println("nWelcome to My Programming Notes' Java Program.");
	   
	   do{// this is the start of the do/while loop	   
		   int sum = 0;
		   
		   // get data from the user
		   System.out.print("nEnter a non negative integer: ");
		   userInput = cin.nextLine();
		   
		   System.out.println("");
		   
		   // if the string isnt a number, dont compute the sum
		   if(!IsNumeric(userInput))
		   {
			   System.out.println(userInput+" is not a number...");
			   System.out.println("Please enter digits only!");	
		   }
		   
		   // if the string is a negative number, dont compute the sum
		   else if(IsNegative(userInput))
		   {
			   System.out.println(userInput+" is a negative number...");
			   System.out.println("Please enter positive digits only!");
		   }
		   
		   // if the string is a decimal number (i.e 19.87), dont compute the sum
		   else if(IsDecimal(userInput))
		   {
			   System.out.println(userInput+" is a decimal number...");
			   System.out.println("Please enter positive whole numbers only!");		  		
		   }
		   
		   // if everything else checks out OK, then compute the sum
		   else
		   {
			   System.out.print("The digits are: ");
			   sum = ComputeSum(userInput); 
			   System.out.println("and the sum is " + sum);
		   }
		   
		   // ask user if they want to enter more data
		   System.out.print("nDo you have more data for input? (Y/N): ");
		   String response = cin.nextLine();
		   response=response.toLowerCase();
		   question = response.charAt(0);
		   
		   System.out.println("n------------------------------------------------");
		   
	   }while(question == 'y');
	   
	   System.out.print("nBYE!n");
   }// end of main
   
   public static boolean IsNumeric(String str)  
   {// checks to see if a string is a number  
	   try
	   { 
		   Double.parseDouble(str);
		   return true;		   
	   }
	   catch(NumberFormatException nfe)
	   { 
		   return false;
	   }
   }// end of IsNumeric
   
   public static boolean IsNegative(String str)  
   {// checks to see if string is a negative number  
	   return Double.parseDouble(str) < 0;
   }// end of IsNegative   
   
   public static boolean IsDecimal(String str)  
   {// checks to see if string is a decimal number  
	   return (Math.floor(Double.parseDouble(str))) != Double.parseDouble(str);
   }// end of IsDecimal
   
   public static int ComputeSum(String userInput)
   {// displays each number individually & computes the sum of the string 
	   int sum = 0;
	   String[] temp = new String[userInput.length()];
	   
	   for(int counter=0; counter < userInput.length(); ++counter)
	   {
		   temp[counter] = userInput.substring(counter,counter+1); 
		   System.out.print(temp[counter] + " ");
		   sum = sum + Integer.parseInt(temp[counter]);
	   }
	   return sum;
   }// end of ComputeSum
}// http://programmingnotes.org/

QUICK NOTES:
The highlighted lines are sections of interest to look out for.

The code is heavily commented, so no further insight is necessary. If you have any questions, feel free to leave a comment below.

Once compiled, you should get this as your output

Welcome to My Programming Notes' Java Program.
Enter a non negative integer: 0 The digits are: 0 and the sum is 0 Do you have more data for input? (Y/N): y ------------------------------------------------ Enter a non negative integer: 39465 The digits are: 3 9 4 6 5 and the sum is 27 Do you have more data for input? (Y/N): y ------------------------------------------------ Enter a non negative integer: H3ll0 W0rld H3ll0 W0rld is not a number... Please enter digits only! Do you have more data for input? (Y/N): y ------------------------------------------------ Enter a non negative integer: -98 -98 is a negative number... Please enter positive digits only! Do you have more data for input? (Y/N): y ------------------------------------------------ Enter a non negative integer: 19.87 19.87 is a decimal number... Please enter positive whole numbers only! Do you have more data for input? (Y/N): n ------------------------------------------------
BYE!

C++ || Class – Roman Numeral To Integer & Integer To Roman Numeral Conversion

April 10, 2012 admin No comments

Click Here For Updated Version Of Program

The following is another homework assignment which was presented in a C++ Data Structures course. This program was assigned in order to practice the use of the class data structure, which is very similar to the struct data structure.

REQUIRED KNOWLEDGE FOR THIS PROGRAM

Header Files - How To Use Them Class - What Is It? Do/While Loop Passing a Value By Reference Roman Numerals - How Do You Convert To Decimal? Online Roman Numeral Converter - Check For Correct Results

This is an interactive program in which the user has the option of selecting from 7 modes of operation. Of those modes, the user has the option of entering in roman numerals for conversion, entering in decimal numbers for conversion, displaying the recently entered number, and finally converting between roman or decimal values.

A sample of the menu is as followed:
(Where the user would enter numbers 1-7 to select a choice)





		
		
			From the following menu:

1.  Enter a Decimal number
2.  Enter a Roman Numeral
3.  Convert from Decimal to Roman
4.  Convert from Roman to Decimal
5.  Print the current Decimal number
6.  Print the current Roman Numeral
7.  Quit

Please enter a selection:
			
				
					
				
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						From the following menu:
 
1.  Enter a Decimal number
2.  Enter a Roman Numeral
3.  Convert from Decimal to Roman
4.  Convert from Roman to Decimal
5.  Print the current Decimal number
6.  Print the current Roman Numeral
7.  Quit
 
Please enter a selection:

This program was implemented into 3 different files (two .cpp files, and one header file .h). So the code for this program will be broken up into 3 sections, the main file (.cpp), the header file (.h), and the implementation of the functions within the header file (.cpp).

======== FILE #1 – Menu.cpp ========

NOTE: On some compilers, you may have to add #include < cstdlib> in order for the code to compile.





		
		
			File #1 - Menu.cpp
			
C++
			
			// ============================================================================
//  File: Menu.cpp
//  Purpose: Converts a number enetered in Decimal to Roman Numeral and a 
//  Roman Numeral to a Decimal Number 
// ============================================================================
#include <iostream>
#include <iomanip>
#include <string>
#include "ClassRomanType.h"
using namespace std;

// function prototypes
void DisplayMenu();
int GetCommand(int command);
void RunChoice(int command, ClassRomanType& romanObject);

int main()
{
	int command=7;	// Holds which action the user chooses to make
	ClassRomanType	romanObject;	// Gives access to the class

	do{
		DisplayMenu();
		command = GetCommand(command);
		RunChoice(command, romanObject);
		cout<<"n--------------------------------------------------------------------n";
	}while(command!=7);

	cout<<"nBye!n";

	return 0;
}// End of main

void RunChoice(int command, ClassRomanType& romanObject)
{// Function: Execute the choice selected from the menu

	// declare private variables
	int decimalNumber=0;	// Holds decimal value
	char romanNumeral[150];	//Holds value of roman numeral

	// execute the desired choice
	cout <<"ntYou selected choice #"<<command<<" which will: ";
	switch(command)
	{
	case 1:
		cout << "Get Decimal Numbernn";
		cout <<"Enter a Decimal Number: ";
		cin >> decimalNumber;
		romanObject.GetDecimalNumber(decimalNumber);
		break;
	case 2:
		cout << "Get Roman Numeralnn";
		cout <<"nEnter a Roman Numeral: ";
		cin >> romanNumeral;
		romanObject.GetRomanNumeral(romanNumeral);
		break;
	case 3:
		cout << "Convert from Decimal to Romannn";
		romanObject.ConvertDecimalToRoman();
		cout<<"Running....nComplete!n";
		break;
	case 4:
		cout << "Convert from Roman to Decimalnn";
		romanObject.ConvertRomanToDecimal();
		cout<<"Running....nComplete!n";
		break;
	case 5:
		cout << "Print the current Decimal numbernn";
		cout<<"n The current Roman to Decimal Value is: "; 
		cout << romanObject.ReturnDecimalNumber()<<endl;
		break;
	case 6:
		cout << "Print the current Roman Numeralnn";
		cout<<"n The current Decimal to Roman Value is: "; 
		cout << romanObject.ReturnRomanNumber()<<endl;
		break;
	case 7:
		cout << "Quitnn";
		break;
	default:
		cout << "nError, you entered an invalid command!nPlease try again...";
		break;
	}
}//End of RunChoice

int GetCommand(int command)
{// Function: Gets choice from menu
	cout <<"nPlease enter a selection: ";
	cin>> command;
	return command;
}// End of GetCommand

void DisplayMenu()
{// Function: Displays menu
	cout <<"From the following menu:n"<<endl;
	cout <<left<<setw(2)<<"1."<<left<<setw(15)<<"  Enter a Decimal number"<<endl;
	cout <<left<<setw(2)<<"2."<<left<<setw(15)<<"  Enter a Roman Numeral"<<endl;
	cout <<left<<setw(2)<<"3."<<left<<setw(15)<<"  Convert from Decimal to Roman"<<endl;
	cout <<left<<setw(2)<<"4."<<left<<setw(15)<<"  Convert from Roman to Decimal"<<endl;
	cout <<left<<setw(2)<<"5."<<left<<setw(15)<<"  Print the current Decimal number"<<endl;
	cout <<left<<setw(2)<<"6."<<left<<setw(15)<<"  Print the current Roman Numeral"<<endl;
	cout <<left<<setw(2)<<"7."<<left<<setw(15)<<"  Quit"<<endl;
}// http://programmingnotes.org/
			
				
					
				
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						// ============================================================================
//  File: Menu.cpp
//  Purpose: Converts a number enetered in Decimal to Roman Numeral and a 
//  Roman Numeral to a Decimal Number 
// ============================================================================
#include <iostream>
#include <iomanip>
#include <string>
#include "ClassRomanType.h"
using namespace std;
 
// function prototypes
void DisplayMenu();
int GetCommand(int command);
void RunChoice(int command, ClassRomanType& romanObject);
 
int main()
{
	int command=7;	// Holds which action the user chooses to make
	ClassRomanType	romanObject;	// Gives access to the class
 
	do{
		DisplayMenu();
		command = GetCommand(command);
		RunChoice(command, romanObject);
		cout<<"n--------------------------------------------------------------------n";
	}while(command!=7);
 
	cout<<"nBye!n";
 
	return 0;
}// End of main
 
void RunChoice(int command, ClassRomanType& romanObject)
{// Function: Execute the choice selected from the menu
 
	// declare private variables
	int decimalNumber=0;	// Holds decimal value
	char romanNumeral[150];	//Holds value of roman numeral
 
	// execute the desired choice
	cout <<"ntYou selected choice #"<<command<<" which will: ";
	switch(command)
	{
	case 1:
		cout << "Get Decimal Numbernn";
		cout <<"Enter a Decimal Number: ";
		cin >> decimalNumber;
		romanObject.GetDecimalNumber(decimalNumber);
		break;
	case 2:
		cout << "Get Roman Numeralnn";
		cout <<"nEnter a Roman Numeral: ";
		cin >> romanNumeral;
		romanObject.GetRomanNumeral(romanNumeral);
		break;
	case 3:
		cout << "Convert from Decimal to Romannn";
		romanObject.ConvertDecimalToRoman();
		cout<<"Running....nComplete!n";
		break;
	case 4:
		cout << "Convert from Roman to Decimalnn";
		romanObject.ConvertRomanToDecimal();
		cout<<"Running....nComplete!n";
		break;
	case 5:
		cout << "Print the current Decimal numbernn";
		cout<<"n The current Roman to Decimal Value is: "; 
		cout << romanObject.ReturnDecimalNumber()<<endl;
		break;
	case 6:
		cout << "Print the current Roman Numeralnn";
		cout<<"n The current Decimal to Roman Value is: "; 
		cout << romanObject.ReturnRomanNumber()<<endl;
		break;
	case 7:
		cout << "Quitnn";
		break;
	default:
		cout << "nError, you entered an invalid command!nPlease try again...";
		break;
	}
}//End of RunChoice
 
int GetCommand(int command)
{// Function: Gets choice from menu
	cout <<"nPlease enter a selection: ";
	cin>> command;
	return command;
}// End of GetCommand
 
void DisplayMenu()
{// Function: Displays menu
	cout <<"From the following menu:n"<<endl;
	cout <<left<<setw(2)<<"1."<<left<<setw(15)<<"  Enter a Decimal number"<<endl;
	cout <<left<<setw(2)<<"2."<<left<<setw(15)<<"  Enter a Roman Numeral"<<endl;
	cout <<left<<setw(2)<<"3."<<left<<setw(15)<<"  Convert from Decimal to Roman"<<endl;
	cout <<left<<setw(2)<<"4."<<left<<setw(15)<<"  Convert from Roman to Decimal"<<endl;
	cout <<left<<setw(2)<<"5."<<left<<setw(15)<<"  Print the current Decimal number"<<endl;
	cout <<left<<setw(2)<<"6."<<left<<setw(15)<<"  Print the current Roman Numeral"<<endl;
	cout <<left<<setw(2)<<"7."<<left<<setw(15)<<"  Quit"<<endl;
}// http://programmingnotes.org/

======== FILE #2 – ClassRomanType.h ========

Remember, you need to name the header file the same as the #include from the Menu.cpp file. This file contains the function declarations, but no implementation of those functions takes place here.





		
		
			File #2 - ClassRomanType.h
			
C++
			
			// ============================================================================
//  File:  ClassRomanType.h
//  Purpose:  Header file for Roman Numeral conversion. It contains all
//  declarations and prototypes for the class members to carry out the 
//  conversion
// ============================================================================
#include <string>
using namespace std;

class   ClassRomanType
{
public:
    ClassRomanType();
          /*   Function: constructor initializes class variables to "0"
               Precondition: none
               Postcondition: defines private variables */

	// member functions
    void GetDecimalNumber(int  decimalNumber);
          /*   Function: gets decimal number
			Precondition: none
			Postcondition: Gets arabic number from user */

    void GetRomanNumeral(char romanNumeral[]);
          /*   Function: gets roman numeral
			Precondition: none
			Postcondition: Gets roman numeral from user */

    void ConvertDecimalToRoman();
          /*   Function: converts decimal number to ronman numeral
			Precondition: arabic and roman numeral characters should be known
			Postcondition: Gets roman numeral from user */

    void ConvertRomanToDecimal();
          /*   Function: converts roman numeral to arabic number 
			Precondition: arabic and roman numeral characters should be known
			Postcondition: Gets decimal number from user */

    int ReturnDecimalNumber();
          /*   Function: displays converted decimal number 
			Precondition: the converted roman numeral to decimal number
			Postcondition: displays decimal number to user */

    string ReturnRomanNumber();
          /*   Function: displays converted roman numeral 
			Precondition: the converted decimal number to roman numeral
			Postcondition: displays roman numeral to user */

    ~ClassRomanType();
          /*   Function: destructor used to return memory to the system 
			Precondition: the converted decimal number to roman numeral
			Postcondition: none */

private:
	char	m_romanValue[150];  // An array holding the roman value within the class
	int	m_decimalValue;	// Holds the final output answer of the roman to decimal conversion
}; // http://programmingnotes.org/
			
				
					
				
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						// ============================================================================
//  File:  ClassRomanType.h
//  Purpose:  Header file for Roman Numeral conversion. It contains all
//  declarations and prototypes for the class members to carry out the 
//  conversion
// ============================================================================
#include <string>
using namespace std;
 
class   ClassRomanType
{
public:
    ClassRomanType();
          /*   Function: constructor initializes class variables to "0"
               Precondition: none
               Postcondition: defines private variables */
 
	// member functions
    void GetDecimalNumber(int  decimalNumber);
          /*   Function: gets decimal number
			Precondition: none
			Postcondition: Gets arabic number from user */
 
    void GetRomanNumeral(char romanNumeral[]);
          /*   Function: gets roman numeral
			Precondition: none
			Postcondition: Gets roman numeral from user */
 
    void ConvertDecimalToRoman();
          /*   Function: converts decimal number to ronman numeral
			Precondition: arabic and roman numeral characters should be known
			Postcondition: Gets roman numeral from user */
 
    void ConvertRomanToDecimal();
          /*   Function: converts roman numeral to arabic number 
			Precondition: arabic and roman numeral characters should be known
			Postcondition: Gets decimal number from user */
 
    int ReturnDecimalNumber();
          /*   Function: displays converted decimal number 
			Precondition: the converted roman numeral to decimal number
			Postcondition: displays decimal number to user */
 
    string ReturnRomanNumber();
          /*   Function: displays converted roman numeral 
			Precondition: the converted decimal number to roman numeral
			Postcondition: displays roman numeral to user */
 
    ~ClassRomanType();
          /*   Function: destructor used to return memory to the system 
			Precondition: the converted decimal number to roman numeral
			Postcondition: none */
 
private:
	char	m_romanValue[150];  // An array holding the roman value within the class
	int	m_decimalValue;	// Holds the final output answer of the roman to decimal conversion
}; // http://programmingnotes.org/

======== FILE #3 – RomanType.cpp ========

This is the function implementation file for the ClassRomanType.h class. This file can be named anything you wish as long as you #include “ClassRomanType.h”





		
		
			File #3 - RomanType.cpp
			
C++
			
			// ============================================================================
//  File:  RomanType.cpp
//  Purpose:  Contains the implementation of the class members for the 
//  roman numeral conversion
//  
//  *NOTE*: Uncomment cout statements to visualize whats happening
// ============================================================================
#include <iostream>
#include <string> 
#include <cstring>
#include "ClassRomanType.h"
using namespace std;

ClassRomanType::ClassRomanType()
{
	m_decimalValue=0;
	strcpy(m_romanValue,"Currently Undefined");
}// end of ClassRomanType

void ClassRomanType:: GetDecimalNumber(int decimalNumber)
{
	m_decimalValue = decimalNumber;
}// end of GetDecimalNumber

void ClassRomanType:: GetRomanNumeral(char romanNumeral[])
{
	strcpy(m_romanValue,romanNumeral);
}// end of GetRomanNumeral

void ClassRomanType:: ConvertDecimalToRoman()
{ 
	strcpy(m_romanValue,""); // erases any previous data
	int numericValue[]={1000,900,500,400,100,90,50,40,10,9,5,4,1,0};
	char *romanNumeral[]={"M","CM","D","CD","C","XC","L"
									,"XL","X","IX","V","IV","I",0};
	
	for (int x=0; numericValue[x] > 0; ++x)
	{
		//cout<<endl<<numericValue[x]<<endl;
		while (m_decimalValue >= numericValue[x])
		{
			//cout<<"current m_decimalValue = " <<m_decimalValue<<endl;
			//cout<<"current numericValue = "<<numericValue[x]<<endl<<endl;
			if(strlen(m_romanValue)==0)
			{
				strcpy(m_romanValue,romanNumeral[x]);
			}
			else
			{
				strcat(m_romanValue,romanNumeral[x]);
			}
			m_decimalValue  -= numericValue[x];
		}
	}
}// end of ConvertDecimalToRoman

void ClassRomanType:: ConvertRomanToDecimal()
{
	 int currentNumber = 0;	// Holds value of each letter numerical value
	 int previousNumber = 0; // Holds the numerical value being compared 
	 m_decimalValue=0; // Resets the current 'romanToDecimalValue' to zero

	 if(strcmp(m_romanValue,"Currently Undefined")!=0)
	 {
		 for (int counter = strlen(m_romanValue)-1; counter >= 0; counter--)
		 {
			 if ((m_romanValue[counter] == 'M') || (m_romanValue[counter] == 'm'))
			 {
				 currentNumber = 1000;
			 }
			 else if ((m_romanValue[counter] == 'D') || (m_romanValue[counter] == 'd'))
			 {
				 currentNumber = 500;
			 }
			 else if ((m_romanValue[counter] == 'C') || (m_romanValue[counter] == 'c'))
			 {
				 currentNumber = 100;
			 }
			 else if ((m_romanValue[counter] == 'L') || (m_romanValue[counter] == 'l'))
			 {
				 currentNumber = 50;
			 }
			 else if ((m_romanValue[counter] == 'X') || (m_romanValue[counter] == 'x'))
			 {
				 currentNumber = 10;
			 }
			 else if ((m_romanValue[counter] == 'V') || (m_romanValue[counter] == 'v'))
			 {
				 currentNumber = 5;
			 }  
			 else if ((m_romanValue[counter] == 'I') || (m_romanValue[counter] == 'i'))
			 {
				 currentNumber = 1;
			 }
			 else
			 {
				 currentNumber = 0;
			 }
			 //cout<<"previousNumber = " <<previousNumber<<endl;
			 //cout<<"currentNumber = " <<currentNumber<<endl;

			 if (previousNumber > currentNumber)
			 {
				 m_decimalValue -= currentNumber;
				 previousNumber = currentNumber;
			 }
			 else
			 {
				 m_decimalValue += currentNumber;
				 previousNumber = currentNumber;
			 }	
			 //cout<<"current m_decimalValue = " <<m_decimalValue<<endl<<endl;
		 }
	 }
}// end of ConvertRomanToDecimal

int ClassRomanType::ReturnDecimalNumber()
{
	return m_decimalValue;
}// end of ReturnDecimalNumber

string ClassRomanType::ReturnRomanNumber()
{
	return  m_romanValue;
}// end of ReturnRomanNumber

ClassRomanType::~ClassRomanType()
{
	m_decimalValue=0;
	strcpy(m_romanValue,"Currently Undefined");
}// http://programmingnotes.org/
			
				
					
				
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						// ============================================================================
//  File:  RomanType.cpp
//  Purpose:  Contains the implementation of the class members for the 
//  roman numeral conversion
//  
//  *NOTE*: Uncomment cout statements to visualize whats happening
// ============================================================================
#include <iostream>
#include <string> 
#include <cstring>
#include "ClassRomanType.h"
using namespace std;
 
ClassRomanType::ClassRomanType()
{
	m_decimalValue=0;
	strcpy(m_romanValue,"Currently Undefined");
}// end of ClassRomanType
 
void ClassRomanType:: GetDecimalNumber(int decimalNumber)
{
	m_decimalValue = decimalNumber;
}// end of GetDecimalNumber
 
void ClassRomanType:: GetRomanNumeral(char romanNumeral[])
{
	strcpy(m_romanValue,romanNumeral);
}// end of GetRomanNumeral
 
void ClassRomanType:: ConvertDecimalToRoman()
{ 
	strcpy(m_romanValue,""); // erases any previous data
	int numericValue[]={1000,900,500,400,100,90,50,40,10,9,5,4,1,0};
	char *romanNumeral[]={"M","CM","D","CD","C","XC","L"
									,"XL","X","IX","V","IV","I",0};
	
	for (int x=0; numericValue[x] > 0; ++x)
	{
		//cout<<endl<<numericValue[x]<<endl;
		while (m_decimalValue >= numericValue[x])
		{
			//cout<<"current m_decimalValue = " <<m_decimalValue<<endl;
			//cout<<"current numericValue = "<<numericValue[x]<<endl<<endl;
			if(strlen(m_romanValue)==0)
			{
				strcpy(m_romanValue,romanNumeral[x]);
			}
			else
			{
				strcat(m_romanValue,romanNumeral[x]);
			}
			m_decimalValue  -= numericValue[x];
		}
	}
}// end of ConvertDecimalToRoman
 
void ClassRomanType:: ConvertRomanToDecimal()
{
	 int currentNumber = 0;	// Holds value of each letter numerical value
	 int previousNumber = 0; // Holds the numerical value being compared 
	 m_decimalValue=0; // Resets the current 'romanToDecimalValue' to zero
 
	 if(strcmp(m_romanValue,"Currently Undefined")!=0)
	 {
		 for (int counter = strlen(m_romanValue)-1; counter >= 0; counter--)
		 {
			 if ((m_romanValue[counter] == 'M') || (m_romanValue[counter] == 'm'))
			 {
				 currentNumber = 1000;
			 }
			 else if ((m_romanValue[counter] == 'D') || (m_romanValue[counter] == 'd'))
			 {
				 currentNumber = 500;
			 }
			 else if ((m_romanValue[counter] == 'C') || (m_romanValue[counter] == 'c'))
			 {
				 currentNumber = 100;
			 }
			 else if ((m_romanValue[counter] == 'L') || (m_romanValue[counter] == 'l'))
			 {
				 currentNumber = 50;
			 }
			 else if ((m_romanValue[counter] == 'X') || (m_romanValue[counter] == 'x'))
			 {
				 currentNumber = 10;
			 }
			 else if ((m_romanValue[counter] == 'V') || (m_romanValue[counter] == 'v'))
			 {
				 currentNumber = 5;
			 }  
			 else if ((m_romanValue[counter] == 'I') || (m_romanValue[counter] == 'i'))
			 {
				 currentNumber = 1;
			 }
			 else
			 {
				 currentNumber = 0;
			 }
			 //cout<<"previousNumber = " <<previousNumber<<endl;
			 //cout<<"currentNumber = " <<currentNumber<<endl;
 
			 if (previousNumber > currentNumber)
			 {
				 m_decimalValue -= currentNumber;
				 previousNumber = currentNumber;
			 }
			 else
			 {
				 m_decimalValue += currentNumber;
				 previousNumber = currentNumber;
			 }	
			 //cout<<"current m_decimalValue = " <<m_decimalValue<<endl<<endl;
		 }
	 }
}// end of ConvertRomanToDecimal
 
int ClassRomanType::ReturnDecimalNumber()
{
	return m_decimalValue;
}// end of ReturnDecimalNumber
 
string ClassRomanType::ReturnRomanNumber()
{
	return  m_romanValue;
}// end of ReturnRomanNumber
 
ClassRomanType::~ClassRomanType()
{
	m_decimalValue=0;
	strcpy(m_romanValue,"Currently Undefined");
}// http://programmingnotes.org/

QUICK NOTES:
The highlighted lines are sections of interest to look out for.

The code is heavily commented, so no further insight is necessary. If you have any questions, feel free to leave a comment below.

Once compiled, you should get this as your output

From the following menu:
1. Enter a Decimal number 2. Enter a Roman Numeral 3. Convert from Decimal to Roman 4. Convert from Roman to Decimal 5. Print the current Decimal number 6. Print the current Roman Numeral 7. Quit Please enter a selection: 9 You selected choice #9 which will: Error, you entered an invalid command! Please try again... -------------------------------------------------------------------- From the following menu: 1. Enter a Decimal number 2. Enter a Roman Numeral 3. Convert from Decimal to Roman 4. Convert from Roman to Decimal 5. Print the current Decimal number 6. Print the current Roman Numeral 7. Quit Please enter a selection: 5 You selected choice #5 which will: Print the current Decimal number The current Roman to Decimal Value is: 0 -------------------------------------------------------------------- From the following menu: 1. Enter a Decimal number 2. Enter a Roman Numeral 3. Convert from Decimal to Roman 4. Convert from Roman to Decimal 5. Print the current Decimal number 6. Print the current Roman Numeral 7. Quit Please enter a selection: 6 You selected choice #6 which will: Print the current Roman Numeral The current Decimal to Roman Value is: Currently Undefined -------------------------------------------------------------------- From the following menu: 1. Enter a Decimal number 2. Enter a Roman Numeral 3. Convert from Decimal to Roman 4. Convert from Roman to Decimal 5. Print the current Decimal number 6. Print the current Roman Numeral 7. Quit Please enter a selection: 1 You selected choice #1 which will: Get Decimal Number Enter a Decimal Number: 1987 -------------------------------------------------------------------- From the following menu: 1. Enter a Decimal number 2. Enter a Roman Numeral 3. Convert from Decimal to Roman 4. Convert from Roman to Decimal 5. Print the current Decimal number 6. Print the current Roman Numeral 7. Quit Please enter a selection: 5 You selected choice #5 which will: Print the current Decimal number The current Roman to Decimal Value is: 1987 -------------------------------------------------------------------- From the following menu: 1. Enter a Decimal number 2. Enter a Roman Numeral 3. Convert from Decimal to Roman 4. Convert from Roman to Decimal 5. Print the current Decimal number 6. Print the current Roman Numeral 7. Quit Please enter a selection: 3 You selected choice #3 which will: Convert from Decimal to Roman Running.... Complete! -------------------------------------------------------------------- From the following menu: 1. Enter a Decimal number 2. Enter a Roman Numeral 3. Convert from Decimal to Roman 4. Convert from Roman to Decimal 5. Print the current Decimal number 6. Print the current Roman Numeral 7. Quit Please enter a selection: 6 You selected choice #6 which will: Print the current Roman Numeral The current Decimal to Roman Value is: MCMLXXXVII -------------------------------------------------------------------- From the following menu: 1. Enter a Decimal number 2. Enter a Roman Numeral 3. Convert from Decimal to Roman 4. Convert from Roman to Decimal 5. Print the current Decimal number 6. Print the current Roman Numeral 7. Quit Please enter a selection: 2 You selected choice #2 which will: Get Roman Numeral Enter a Roman Numeral: mMxiI -------------------------------------------------------------------- From the following menu: 1. Enter a Decimal number 2. Enter a Roman Numeral 3. Convert from Decimal to Roman 4. Convert from Roman to Decimal 5. Print the current Decimal number 6. Print the current Roman Numeral 7. Quit Please enter a selection: 6 You selected choice #6 which will: Print the current Roman Numeral The current Decimal to Roman Value is: mMxiI -------------------------------------------------------------------- From the following menu: 1. Enter a Decimal number 2. Enter a Roman Numeral 3. Convert from Decimal to Roman 4. Convert from Roman to Decimal 5. Print the current Decimal number 6. Print the current Roman Numeral 7. Quit Please enter a selection: 4 You selected choice #4 which will: Convert from Roman to Decimal Running.... Complete! -------------------------------------------------------------------- From the following menu: 1. Enter a Decimal number 2. Enter a Roman Numeral 3. Convert from Decimal to Roman 4. Convert from Roman to Decimal 5. Print the current Decimal number 6. Print the current Roman Numeral 7. Quit Please enter a selection: 5 You selected choice #5 which will: Print the current Decimal number The current Roman to Decimal Value is: 2012 -------------------------------------------------------------------- From the following menu: 1. Enter a Decimal number 2. Enter a Roman Numeral 3. Convert from Decimal to Roman 4. Convert from Roman to Decimal 5. Print the current Decimal number 6. Print the current Roman Numeral 7. Quit Please enter a selection: 7
You selected choice #7 which will: Quit -------------------------------------------------------------------- Bye!

C++ || Class – A Simple Calculator Implementation Using A Class, Enum List, Typedef & Header Files

February 11, 2012 admin No comments

The following is another homework assignment which was presented in a programming class, that was used to introduce the concept of the class data structure, which is very similar to the struct data structure.

REQUIRED KNOWLEDGE FOR THIS PROGRAM

Header Files - How To Use Them Class - Data Structure Enumerated List Typedef Do/While Loop Passing a Value By Reference Constant Variables Atoi - Convert String To Int Value

This is an interactive program which simulates a basic arithmetic calculator, where the user has the option of selecting from 9 modes of operation. Of those modes, the user has the option of adding, subtracting, multiplying, and dividing two numbers together. Also included in the calculator is a mode which deducts percentages from any given variable the user desires, so for example, if the user wanted to deduct 23% from the number 87, the program would display the reduced value of 66.99.

A sample of the menu is as followed:
(Where the user would enter numbers 1-9 to select a choice)





		
		
			Calculator Options:
  1) Clear Calculator
  2) Set Initial Calculator Value
  3) Display The Current Value
  4) Add
  5) Subtract
  6) Divide
  7) Multiply
  8) Percentage Calculator
  9) Quit

Please enter a selection:
			
				
					
				
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						Calculator Options:
  1) Clear Calculator
  2) Set Initial Calculator Value
  3) Display The Current Value
  4) Add
  5) Subtract
  6) Divide
  7) Multiply
  8) Percentage Calculator
  9) Quit
 
Please enter a selection:

NOTE: On some compilers, you may have to add #include < cstdlib> in order for the code to compile.

======== File #1 Main.cpp ========





		
		
			File #1 - main.cpp
			
C++
			
			// ============================================================================
// This program tests the CCalc class. A loop is entered where the user is
// prompted for a simple mathematical operation to be performed by the CCalc
// class. The user is allowed to manipulate the calculator until they
// indicate they wish to quit.
// ============================================================================
#include <iostream>
#include <iomanip>
#include "CCalc.h"
using namespace std;


// defined constants
const   int         LENGTH = 81;

// function prototypes
void    DisplayMenu();
void    HandleMenuSelection(CCalc  &calcObject, int  menuItem);

// enumerated list
enum    MenuChoice  { ITEM_CLEAR = 1
                    , ITEM_SET_VALUE = 2
                    , ITEM_DISPLAY_VALUE = 3
                    , ITEM_ADD = 4
                    , ITEM_SUBTRACT = 5
                    , ITEM_DIVIDE = 6
                    , ITEM_MULTIPLY = 7
                    , ITEM_PERCENT = 8
                    , ITEM_QUIT = 9};

// ==== main ==================================================================
//
// ============================================================================

int  main()
{
    // variable declarations
    CCalc       calculator;  // 'calculator' is an accessor to the 'CCalc' class
    char        myString[LENGTH];
    int         menuItem=0;

    // initialize the calculator
    calculator.SetCurrentValue(0);

    // loop and let the user manipulate the calculator
    do{
	       // display the menu and get the user selection
        DisplayMenu();
        cout << "nPlease enter a selection: ";
        cin.getline(myString, LENGTH);

        // convert the ascii string into an integer
        menuItem = atoi(myString);

        // creates a line seperator after each task is executed
        cout<<setfill('-');
        cout<<left<<setw(30)<<""<<right<<setw(30)<<""<<endl; 
		
        // handle the menu selection
        HandleMenuSelection(calculator, menuItem);
        cout <<endl;
		
        // creates a line seperator after each task is executed
        cout<<setfill('-');
        cout<<left<<setw(30)<<""<<right<<setw(30)<<""<<endl; 

        // ensures the menu isnt displayed twice on the screen
        if(menuItem!=1 && menuItem!=3 && menuItem!=9)
        {
		   cin.ignore();
        }
	}while(menuItem!=ITEM_QUIT);

	cout << "nBye....n";

	return 0;
}  // end of "main"

// ==== DisplayMenu ===========================================================
//
// This function displays the menu of options to stdout.
//
// Input:  nothing
//
// Output: nothing
//
// ============================================================================
void    DisplayMenu()
{
    cout << "Calculator Options:" << endl;
    cout << "  1) Clear Calculator" << endl;
    cout << "  2) Set Initial Calculator Value" << endl;
    cout << "  3) Display The Current Value" << endl;
    cout << "  4) Add" << endl;
    cout << "  5) Subtract" << endl;
    cout << "  6) Divide" << endl;
    cout << "  7) Multiply" << endl;
    cout << "  8) Percentage Calculator" << endl;
    cout << "  9) Quit" << endl;
}  // end of "DisplayMenu"

// ==== HandleMenuSelection ===================================================
//
// This function handles the menu selection by examining the input integer
// value and calling the appropriate function.
//
// Input:
//      calculator      -- a reference to the CCalc class
//
//      menuItem        -- an integer representing the current menu selection
//
// Output:
//      The desired user selection
//
// ============================================================================
void   HandleMenuSelection(CCalc  &calculator, int  menuItem)
{
	double currentValue = 0;
	double prevNum = calculator.GetPreviousValue();

	// checks to see which user defined selection the calculator will execute
	// as defined in the enum list located above the main function.
	// A switch would be more practical to be used here, but i wasnt 
	// comfortable yet using switches when this program was initially made
	if (menuItem == ITEM_CLEAR)
	{
		cout << "nThe current value is " << calculator.Clear() << endl;
	}
	// set a initial value
	else if (menuItem == ITEM_SET_VALUE)
	{
		cout << "nPlease enter a new value to assign: ";
		cin >> currentValue;
		calculator.SetCurrentValue(currentValue);
	}
	// display current value
	else if (menuItem == ITEM_DISPLAY_VALUE)
	{
		cout << "nThe current value is: "<< calculator.DisplayCurrentValue() <<endl;
	}
	// add current number by another number
	else if (menuItem == ITEM_ADD)
	{
		cout << "nThe current value is: "<< prevNum <<endl;
		cout << "nPlease enter a number to be added to "<<prevNum<<": ";
		cin >> currentValue;	

		calculator.Add(currentValue);
		cout << "n"<<prevNum<<" + "<<currentValue<<" = "<< calculator.DisplayCurrentValue() <<endl;
	}
	// subtract current number by another number
	else if (menuItem == ITEM_SUBTRACT)
	{
		cout << "nThe current value is: "<< prevNum <<endl;
		cout << "nPlease enter a number to be subtracted from "<<prevNum<<": ";
		cin >> currentValue;

		calculator.Subtract(currentValue);
		cout << "n"<<prevNum<<" - "<<currentValue<<" = "
			<< calculator.DisplayCurrentValue() <<endl;
	}
	// divide current value by another number
	else if (menuItem == ITEM_DIVIDE)
	{
		cout << "nThe current value is: "<< prevNum <<endl;
		cout << "nPlease enter a divisor to be divided by "<<prevNum<<": ";
		cin >> currentValue;
		if (currentValue == 0)
		{
			cout << "nSorry, division by zero is not allowed...nPlease press ENTER to continue...";
			cin.get();
		}
		else
		{
			calculator.Divide(currentValue);
			cout << "n"<<prevNum<<" "<<char(246)<<" "<<currentValue<<" = "
				<< calculator.DisplayCurrentValue() <<endl;
		}
	}
	    // multiply current value by another number
	else if (menuItem == ITEM_MULTIPLY)
	{
		cout << "nThe current value is: "<< prevNum <<endl;
		cout << "nPlease enter a number to be multiplied by "<<prevNum<<": ";
		cin >> currentValue;
		
		calculator.Multiply(currentValue);
		cout << "n"<<prevNum<<" x "<<currentValue<<" = "
			<< calculator.DisplayCurrentValue() <<endl;
	}
	// convert value to decimal percent
	else if (menuItem == ITEM_PERCENT) 
	{
		cout << "nThe current value is: "<< prevNum <<endl;
		cout << "nPlease enter a percentage to be deducted from "<<prevNum<<": ";
		cin >> currentValue;
		
		cout << "n"<<currentValue<<"% off of "<<prevNum<<" is "
			<< calculator.GetPercentage(currentValue) <<endl;
	}
	// quit program
	else if (menuItem == ITEM_QUIT) 
	{
		cout << "nCalculator will now quit";
	}
	// user entered an invalid choice
	else
	{
		cout << "nYou have entered an invalid command...nPlease press ENTER to try again.";
	}
}  // http://programmingnotes.org/
			
				
					
				
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						// ============================================================================
// This program tests the CCalc class. A loop is entered where the user is
// prompted for a simple mathematical operation to be performed by the CCalc
// class. The user is allowed to manipulate the calculator until they
// indicate they wish to quit.
// ============================================================================
#include <iostream>
#include <iomanip>
#include "CCalc.h"
using namespace std;
 
 
// defined constants
const   int         LENGTH = 81;
 
// function prototypes
void    DisplayMenu();
void    HandleMenuSelection(CCalc  &calcObject, int  menuItem);
 
// enumerated list
enum    MenuChoice  { ITEM_CLEAR = 1
                    , ITEM_SET_VALUE = 2
                    , ITEM_DISPLAY_VALUE = 3
                    , ITEM_ADD = 4
                    , ITEM_SUBTRACT = 5
                    , ITEM_DIVIDE = 6
                    , ITEM_MULTIPLY = 7
                    , ITEM_PERCENT = 8
                    , ITEM_QUIT = 9};
 
// ==== main ==================================================================
//
// ============================================================================
 
int  main()
{
    // variable declarations
    CCalc       calculator;  // 'calculator' is an accessor to the 'CCalc' class
    char        myString[LENGTH];
    int         menuItem=0;
 
    // initialize the calculator
    calculator.SetCurrentValue(0);
 
    // loop and let the user manipulate the calculator
    do{
	       // display the menu and get the user selection
        DisplayMenu();
        cout << "nPlease enter a selection: ";
        cin.getline(myString, LENGTH);
 
        // convert the ascii string into an integer
        menuItem = atoi(myString);
 
        // creates a line seperator after each task is executed
        cout<<setfill('-');
        cout<<left<<setw(30)<<""<<right<<setw(30)<<""<<endl; 
		
        // handle the menu selection
        HandleMenuSelection(calculator, menuItem);
        cout <<endl;
		
        // creates a line seperator after each task is executed
        cout<<setfill('-');
        cout<<left<<setw(30)<<""<<right<<setw(30)<<""<<endl; 
 
        // ensures the menu isnt displayed twice on the screen
        if(menuItem!=1 && menuItem!=3 && menuItem!=9)
        {
		   cin.ignore();
        }
	}while(menuItem!=ITEM_QUIT);
 
	cout << "nBye....n";
 
	return 0;
}  // end of "main"
 
// ==== DisplayMenu ===========================================================
//
// This function displays the menu of options to stdout.
//
// Input:  nothing
//
// Output: nothing
//
// ============================================================================
void    DisplayMenu()
{
    cout << "Calculator Options:" << endl;
    cout << "  1) Clear Calculator" << endl;
    cout << "  2) Set Initial Calculator Value" << endl;
    cout << "  3) Display The Current Value" << endl;
    cout << "  4) Add" << endl;
    cout << "  5) Subtract" << endl;
    cout << "  6) Divide" << endl;
    cout << "  7) Multiply" << endl;
    cout << "  8) Percentage Calculator" << endl;
    cout << "  9) Quit" << endl;
}  // end of "DisplayMenu"
 
// ==== HandleMenuSelection ===================================================
//
// This function handles the menu selection by examining the input integer
// value and calling the appropriate function.
//
// Input:
//      calculator      -- a reference to the CCalc class
//
//      menuItem        -- an integer representing the current menu selection
//
// Output:
//      The desired user selection
//
// ============================================================================
void   HandleMenuSelection(CCalc  &calculator, int  menuItem)
{
	double currentValue = 0;
	double prevNum = calculator.GetPreviousValue();
 
	// checks to see which user defined selection the calculator will execute
	// as defined in the enum list located above the main function.
	// A switch would be more practical to be used here, but i wasnt 
	// comfortable yet using switches when this program was initially made
	if (menuItem == ITEM_CLEAR)
	{
		cout << "nThe current value is " << calculator.Clear() << endl;
	}
	// set a initial value
	else if (menuItem == ITEM_SET_VALUE)
	{
		cout << "nPlease enter a new value to assign: ";
		cin >> currentValue;
		calculator.SetCurrentValue(currentValue);
	}
	// display current value
	else if (menuItem == ITEM_DISPLAY_VALUE)
	{
		cout << "nThe current value is: "<< calculator.DisplayCurrentValue() <<endl;
	}
	// add current number by another number
	else if (menuItem == ITEM_ADD)
	{
		cout << "nThe current value is: "<< prevNum <<endl;
		cout << "nPlease enter a number to be added to "<<prevNum<<": ";
		cin >> currentValue;	
 
		calculator.Add(currentValue);
		cout << "n"<<prevNum<<" + "<<currentValue<<" = "<< calculator.DisplayCurrentValue() <<endl;
	}
	// subtract current number by another number
	else if (menuItem == ITEM_SUBTRACT)
	{
		cout << "nThe current value is: "<< prevNum <<endl;
		cout << "nPlease enter a number to be subtracted from "<<prevNum<<": ";
		cin >> currentValue;
 
		calculator.Subtract(currentValue);
		cout << "n"<<prevNum<<" - "<<currentValue<<" = "
			<< calculator.DisplayCurrentValue() <<endl;
	}
	// divide current value by another number
	else if (menuItem == ITEM_DIVIDE)
	{
		cout << "nThe current value is: "<< prevNum <<endl;
		cout << "nPlease enter a divisor to be divided by "<<prevNum<<": ";
		cin >> currentValue;
		if (currentValue == 0)
		{
			cout << "nSorry, division by zero is not allowed...nPlease press ENTER to continue...";
			cin.get();
		}
		else
		{
			calculator.Divide(currentValue);
			cout << "n"<<prevNum<<" "<<char(246)<<" "<<currentValue<<" = "
				<< calculator.DisplayCurrentValue() <<endl;
		}
	}
	    // multiply current value by another number
	else if (menuItem == ITEM_MULTIPLY)
	{
		cout << "nThe current value is: "<< prevNum <<endl;
		cout << "nPlease enter a number to be multiplied by "<<prevNum<<": ";
		cin >> currentValue;
		
		calculator.Multiply(currentValue);
		cout << "n"<<prevNum<<" x "<<currentValue<<" = "
			<< calculator.DisplayCurrentValue() <<endl;
	}
	// convert value to decimal percent
	else if (menuItem == ITEM_PERCENT) 
	{
		cout << "nThe current value is: "<< prevNum <<endl;
		cout << "nPlease enter a percentage to be deducted from "<<prevNum<<": ";
		cin >> currentValue;
		
		cout << "n"<<currentValue<<"% off of "<<prevNum<<" is "
			<< calculator.GetPercentage(currentValue) <<endl;
	}
	// quit program
	else if (menuItem == ITEM_QUIT) 
	{
		cout << "nCalculator will now quit";
	}
	// user entered an invalid choice
	else
	{
		cout << "nYou have entered an invalid command...nPlease press ENTER to try again.";
	}
}  // http://programmingnotes.org/

======== File #2 CCalc.h. ========

Remember, you need to name the header file the same as the #include from the main.cpp file. This file contains the function declarations, but no implementation of those functions takes place here.





		
		
			File #2 - CCalc.h
			
C++
			
			// ============================================================================
// File: CCalc.h
// ============================================================================
// This is the header file for the CCalc class.
// ============================================================================

#ifndef CCALC_HEADER
#define CCALC_HEADER

// a typedef statement to create a synonym for 
// the 'double' data type named "CCalcType"
typedef	double CCalcType;

class   CCalc    // this is the 'CCalc' class declaration
{
public:
    // constructor
    CCalc(); // initializes variables

    // member functions
    void        Add(CCalcType  value); // adds numbers together
    CCalcType   Clear();  // clears the current number in the calculator
    void        Divide(CCalcType  value); // divides numbers together
    CCalcType   DisplayCurrentValue(); // displays the current value in the calculator
    CCalcType   GetPreviousValue(); // returns the previous value in the calculator
    CCalcType   GetPercentage(CCalcType  value); // deducts a user specified percentage of a given value
    void        Multiply(CCalcType  value); // multiplies numbers together
    void        SetCurrentValue(CCalcType  value); // set a current value in the calculator
    void        Subtract(CCalcType  value); // subtracts two numbers together

     // destructor
     ~CCalc();  // deletes any variables contained in the class

private:
    CCalcType   m_total; // private variable used within the program
};
#endif  // CCALC_HEADER -- http://programmingnotes.org/
			
				
					
				
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						// ============================================================================
// File: CCalc.h
// ============================================================================
// This is the header file for the CCalc class.
// ============================================================================
 
#ifndef CCALC_HEADER
#define CCALC_HEADER
 
// a typedef statement to create a synonym for 
// the 'double' data type named "CCalcType"
typedef	double CCalcType;
 
class   CCalc    // this is the 'CCalc' class declaration
{
public:
    // constructor
    CCalc(); // initializes variables
 
    // member functions
    void        Add(CCalcType  value); // adds numbers together
    CCalcType   Clear();  // clears the current number in the calculator
    void        Divide(CCalcType  value); // divides numbers together
    CCalcType   DisplayCurrentValue(); // displays the current value in the calculator
    CCalcType   GetPreviousValue(); // returns the previous value in the calculator
    CCalcType   GetPercentage(CCalcType  value); // deducts a user specified percentage of a given value
    void        Multiply(CCalcType  value); // multiplies numbers together
    void        SetCurrentValue(CCalcType  value); // set a current value in the calculator
    void        Subtract(CCalcType  value); // subtracts two numbers together
 
     // destructor
     ~CCalc();  // deletes any variables contained in the class
 
private:
    CCalcType   m_total; // private variable used within the program
};
#endif  // CCALC_HEADER -- http://programmingnotes.org/

======== File #3 CCalc.cpp. ========

This is the function implementation file for the CCalc.h class. This file can be named anything you wish as long as you #include “CCalc.h”





		
		
			File #3 - CCalc.cpp
			
C++
			
			// ============================================================================
// File: CCalc.cpp
// ============================================================================
// This is the function implementation file for the CCalc.h class.
// ============================================================================
#include <iostream>
#include "CCalc.h"
using namespace std;

CCalc::CCalc() // this is the constructor
{
	m_total = 0;
}// end of CCalc

void CCalc::Add(CCalcType  value)
{
	m_total += value;
}// end of Add

CCalcType CCalc::Clear()
{
	m_total = 0;
	return m_total;
}// end of Clear

void CCalc::Divide(CCalcType  value)
{
	m_total /= value;
}// end of Divide

CCalcType CCalc::DisplayCurrentValue()
{
	return m_total;
}// end of DisplayCurrentValue

CCalcType CCalc::GetPreviousValue()
{
	return m_total;
}// end of GetPreviousValue

void CCalc::Multiply(CCalcType  value)
{
	m_total *= value;
}// end if Multiply

void CCalc::SetCurrentValue(CCalcType  value)
{
	m_total = value;
}// end of SetValue

void CCalc::Subtract(CCalcType  value)
{
	m_total -= value;
}// end of Subtract

CCalcType CCalc::GetPercentage(CCalcType  value)
{
	CCalcType percent= value/100;
	CCalcType tempTotal = m_total; 

	tempTotal *= percent;
	m_total -= tempTotal;

	return m_total;
}// end of GetPercentage

CCalc::~CCalc() // this is the destructor
{
	m_total = 0;
}// http://programmingnotes.org/
			
				
					
				
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						// ============================================================================
// File: CCalc.cpp
// ============================================================================
// This is the function implementation file for the CCalc.h class.
// ============================================================================
#include <iostream>
#include "CCalc.h"
using namespace std;
 
CCalc::CCalc() // this is the constructor
{
	m_total = 0;
}// end of CCalc
 
void CCalc::Add(CCalcType  value)
{
	m_total += value;
}// end of Add
 
CCalcType CCalc::Clear()
{
	m_total = 0;
	return m_total;
}// end of Clear
 
void CCalc::Divide(CCalcType  value)
{
	m_total /= value;
}// end of Divide
 
CCalcType CCalc::DisplayCurrentValue()
{
	return m_total;
}// end of DisplayCurrentValue
 
CCalcType CCalc::GetPreviousValue()
{
	return m_total;
}// end of GetPreviousValue
 
void CCalc::Multiply(CCalcType  value)
{
	m_total *= value;
}// end if Multiply
 
void CCalc::SetCurrentValue(CCalcType  value)
{
	m_total = value;
}// end of SetValue
 
void CCalc::Subtract(CCalcType  value)
{
	m_total -= value;
}// end of Subtract
 
CCalcType CCalc::GetPercentage(CCalcType  value)
{
	CCalcType percent= value/100;
	CCalcType tempTotal = m_total; 
 
	tempTotal *= percent;
	m_total -= tempTotal;
 
	return m_total;
}// end of GetPercentage
 
CCalc::~CCalc() // this is the destructor
{
	m_total = 0;
}// http://programmingnotes.org/

QUICK NOTES:
The highlighted lines are sections of interest to look out for.

The code is heavily commented, so no further insight is necessary. If you have any questions, feel free to leave a comment below.

Once compiled, you should get this as your output

Calculator Options: 1) Clear Calculator 2) Set Initial Calculator Value 3) Display The Current Value 4) Add 5) Subtract 6) Divide 7) Multiply 8.) Percentage Calculator 9) Quit
Please enter a selection: 0 ------------------------------------------------------------ You have entered an invalid command... Please ENTER to try again. ------------------------------------------------------------ Calculator Options: 1) Clear Calculator 2) Set Initial Calculator Value 3) Display The Current Value 4) Add 5) Subtract 6) Divide 7) Multiply 8.) Percentage Calculator 9) Quit Please enter a selection: 2 ------------------------------------------------------------ Please enter a new value to assign: 2 ------------------------------------------------------------ Calculator Options: 1) Clear Calculator 2) Set Initial Calculator Value 3) Display The Current Value 4) Add 5) Subtract 6) Divide 7) Multiply 8.) Percentage Calculator 9) Quit Please enter a selection: 3 ------------------------------------------------------------ The current value is: 2 ------------------------------------------------------------ Calculator Options: 1) Clear Calculator 2) Set Initial Calculator Value 3) Display The Current Value 4) Add 5) Subtract 6) Divide 7) Multiply 8.) Percentage Calculator 9) Quit Please enter a selection: 4 ------------------------------------------------------------ The current value is: 2 Please enter a number to be added to 2: 2 2 + 2 = 4 ------------------------------------------------------------ Calculator Options: 1) Clear Calculator 2) Set Initial Calculator Value 3) Display The Current Value 4) Add 5) Subtract 6) Divide 7) Multiply 8.) Percentage Calculator 9) Quit Please enter a selection: 5 ------------------------------------------------------------ The current value is: 4 Please enter a number to be subtracted from 4: 6 4 - 6 = -2 ------------------------------------------------------------ Calculator Options: 1) Clear Calculator 2) Set Initial Calculator Value 3) Display The Current Value 4) Add 5) Subtract 6) Divide 7) Multiply 8.) Percentage Calculator 9) Quit Please enter a selection: 6 ------------------------------------------------------------ The current value is: -2 Please enter a divisor to be divided by -2: -2 -2 ÷ -2 = 1 ------------------------------------------------------------ Calculator Options: 1) Clear Calculator 2) Set Initial Calculator Value 3) Display The Current Value 4) Add 5) Subtract 6) Divide 7) Multiply 8.) Percentage Calculator 9) Quit Please enter a selection: 7 ------------------------------------------------------------ The current value is: 1 Please enter a number to be multiplied by 1: 87 1 x 87 = 87 ------------------------------------------------------------ Calculator Options: 1) Clear Calculator 2) Set Initial Calculator Value 3) Display The Current Value 4) Add 5) Subtract 6) Divide 7) Multiply 8.) Percentage Calculator 9) Quit Please enter a selection: 8 ------------------------------------------------------------ The current value is: 87 Please enter a percentage to be deducted from 87: 23 23% off of 87 is 66.99 ------------------------------------------------------------ Calculator Options: 1) Clear Calculator 2) Set Initial Calculator Value 3) Display The Current Value 4) Add 5) Subtract 6) Divide 7) Multiply 8.) Percentage Calculator 9) Quit Please enter a selection: 9 ------------------------------------------------------------ Calculator will now quit ------------------------------------------------------------
Bye....

C++ || Modulus – Celsius To Fahrenheit Conversion Displaying Degrees Divisible By 10 Using Modulus

February 02, 2012 admin No comments

This page will consist of two simple programs which demonstrate the use of the modulus operator (%).

REQUIRED KNOWLEDGE FOR THIS PROGRAM

Modulus Do/While Loop Functions Simple Math - Divisibility Celsius to Fahrenheit Conversion

===== FINDING THE DIVISIBILITY OF A NUMBER =====

Take a simple arithmetic problem: what’s left over when you divide an odd number by an even number? The answer may not be easy to compute, but we know that it will most likely result in an answer which has a decimal remainder. How would we determine the divisibility of a number in a programming language like C++? That’s where the modulus operator comes in handy.





		
		
			Is It Divisible?
			
C++
			
			#include <iostream>
using namespace std;

int main()
{
	// declare variables
	int base=0;
	int userInput=0;
	double multiple =0;

	// get first number
	cout <<"Please enter a value: ";
	cin >> base;

	// get second number
	cout << "nPlease enter a factor of "<<base<<": ";
	cin >> userInput;

	do{ // loop will keep going until the user enters a correct answer

		// this is the modulus declaration, which will find the 
		// remainder between the 2 numbers
		multiple = base % userInput;

		// if the modulus result returns 0, the 2 numbers
		// are divisible
		if (multiple == 0)
		{
			cout <<"nCorrect! " << base << " is divisible by " << userInput <<endl;
			cout <<"n("<< base << "/" << userInput <<") = "<<(base/userInput)<<endl;
		}

		// if the user entered an incorrect choice, promt an error message
		else
		{
			cout << "nIncorrect, " << base <<" is not divisible by "
				<< userInput <<".nPlease enter a new multiple integer for that value: ";
			cin >> userInput;
		}
	}while(multiple != 0);

	// ^ loop stops once user enters correct choice

	return 0;
}// http://programmingnotes.org/
			
				
					
				
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						#include <iostream>
using namespace std;
 
int main()
{
	// declare variables
	int base=0;
	int userInput=0;
	double multiple =0;
 
	// get first number
	cout <<"Please enter a value: ";
	cin >> base;
 
	// get second number
	cout << "nPlease enter a factor of "<<base<<": ";
	cin >> userInput;
 
	do{ // loop will keep going until the user enters a correct answer
 
		// this is the modulus declaration, which will find the 
		// remainder between the 2 numbers
		multiple = base % userInput;
 
		// if the modulus result returns 0, the 2 numbers
		// are divisible
		if (multiple == 0)
		{
			cout <<"nCorrect! " << base << " is divisible by " << userInput <<endl;
			cout <<"n("<< base << "/" << userInput <<") = "<<(base/userInput)<<endl;
		}
 
		// if the user entered an incorrect choice, promt an error message
		else
		{
			cout << "nIncorrect, " << base <<" is not divisible by "
				<< userInput <<".nPlease enter a new multiple integer for that value: ";
			cin >> userInput;
		}
	}while(multiple != 0);
 
	// ^ loop stops once user enters correct choice
 
	return 0;
}// http://programmingnotes.org/

To demonstrate the above code, here is a sample run:

Please enter a value: 21 Please enter a factor of 21: 5
Incorrect, 21 is not divisible by 5. Please enter a new multiple integer for that value: 7
Correct! 21 is divisible by 7 (21/7) = 3

===== CELSIUS TO FAHRENHEIT CONVERSION =====





		
		
			Celsius To Fahrenheit Conversion
			
C++
			
			#include <iostream>
using namespace std;

// function prototype
double ConvertCelsiusToFahrenheit(int degree);

int main()
{
	// declare variables
	int low=0;
	int high=0;
	double degreeFahrenhiet =0;
	double multiple =0;

	// get data from user
	cout << "Enter a low number: ";
	cin >> low;

	cout << "nEnter a high number: ";
	cin >> high;
	
	// displays data back to user in table form
	cout <<"nCelsius Fahrenheit:n";
	cout << low << "t" << ConvertCelsiusToFahrenheit(low)<<endl;
	++low;

	// this loop displays all the degrees that are divisible by 10
	do{ 
		// this converts the current number from celsius to fahrenhiet
		degreeFahrenhiet = ConvertCelsiusToFahrenheit(low);

		// this is the modulus operation which finds the 
		// numbers which are divisible by 10
		multiple = low % 10;		

		// the program will only display the degrees to the user via
		// cout which are divisible by 10
		if(multiple ==0)
		{
			cout << low << "t" << degreeFahrenhiet<<endl;
		}
		
		// this increments the current degree number by 1
		++low;
	}while(low < high);
	// ^ loop stops once the 'low' variable reaches the 'high' variable

	// displays the 'high' converted degrees to the user
	cout << high << "t" << ConvertCelsiusToFahrenheit(high)<<endl;

	return 0;
}// end of main

// function declaration which returns the converted celsius to fahrenhiet value
double ConvertCelsiusToFahrenheit(int degree)
{
	return ((1.8 * degree) + 32.0);
}// http://programmingnotes.org/
			
				
					
				
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						#include <iostream>
using namespace std;
 
// function prototype
double ConvertCelsiusToFahrenheit(int degree);
 
int main()
{
	// declare variables
	int low=0;
	int high=0;
	double degreeFahrenhiet =0;
	double multiple =0;
 
	// get data from user
	cout << "Enter a low number: ";
	cin >> low;
 
	cout << "nEnter a high number: ";
	cin >> high;
	
	// displays data back to user in table form
	cout <<"nCelsius Fahrenheit:n";
	cout << low << "t" << ConvertCelsiusToFahrenheit(low)<<endl;
	++low;
 
	// this loop displays all the degrees that are divisible by 10
	do{ 
		// this converts the current number from celsius to fahrenhiet
		degreeFahrenhiet = ConvertCelsiusToFahrenheit(low);
 
		// this is the modulus operation which finds the 
		// numbers which are divisible by 10
		multiple = low % 10;		
 
		// the program will only display the degrees to the user via
		// cout which are divisible by 10
		if(multiple ==0)
		{
			cout << low << "t" << degreeFahrenhiet<<endl;
		}
		
		// this increments the current degree number by 1
		++low;
	}while(low < high);
	// ^ loop stops once the 'low' variable reaches the 'high' variable
 
	// displays the 'high' converted degrees to the user
	cout << high << "t" << ConvertCelsiusToFahrenheit(high)<<endl;
 
	return 0;
}// end of main
 
// function declaration which returns the converted celsius to fahrenhiet value
double ConvertCelsiusToFahrenheit(int degree)
{
	return ((1.8 * degree) + 32.0);
}// http://programmingnotes.org/

QUICK NOTES:
The highlighted lines are sections of interest to look out for.

The code is heavily commented, so no further insight is necessary. If you have any questions, feel free to leave a comment below.

Once compiled, you should get this as your output

Enter a low number: 3 Enter a high number: 303
Celsius Fahrenheit: 3..........37.4 10.........50 20.........68 30.........86 40........104 50........122 60........140 70........158 80........176 90........194 100.......212 110.......230 120.......248 130.......266 140.......284 150.......302 160.......320 170.......338 180.......356 190.......374 200.......392 210.......410 220.......428 230.......446 240.......464 250.......482 260.......500 270.......518 280.......536 290.......554 300.......572 303.......577.4

C++ || Random Number Guessing Game Using Srand, Rand, & Do/While Loop

January 20, 2012 admin 2 Comments

This is a simple guessing game, which demonstrates the use of srand and rand to generate random numbers. This program first prompts the user to enter a number between 1 and 1000. Using if/else statements, the program will then check to see if the user inputted number is higher/lower than the pre defined random number which is generated by the program. If the user makes a wrong guess, the program will re prompt the user to enter in a new number, where they will have a chance to enter in a new guess. Once the user finally guesses the correct answer, using a do/while loop, the program will ask if they want to play again. If the user selects yes, the game will start over, and a new random number will be generated. If the user selects no, the game will end.

REQUIRED KNOWLEDGE FOR THIS PROGRAM

Srand Rand Modulus Ctime Do/While Loop

NOTE: On some compilers, you may have to add #include < cstdlib> in order for the code to compile.





		
		
			I'm Thinking of a Number Between 1 and 1000...
			
C++
			
			// ============================================================================
//    Author: Kenneth Perkins
//    Date:   Jan 20, 2012
//    Taken From: http://programmingnotes.org/
//    File:  guessingGame.cpp
//    Description: Demonstrates a simple random number guessing game
// ============================================================================
#include <iostream>
#include <ctime>
#include <iomanip>
using namespace std;

int main() 
{
	// declare & initialize variables
	char playAgain = 'y';
	int userInput = 0;
	int numGuesses = 0;
	// Seed the random number generator with the current time so
     // the numbers will be different every time the program runs
	srand(time(NULL));
	int randomNumber = rand() % 1000+1;

	// display directions to user
	cout << "I'm thinking of a number between 1 and 1000. Go ahead and make your first guess.\n\n";
 
	do{ // this is the start of the do/while loop

		// get data from user
		cin >> userInput;
		
		// increments the 'numGuesses' variable each time the user 
		// gets the guess wrong
		++numGuesses;
		
		// if user guess is too high, do this code
		if(userInput > randomNumber) 
		{
			cout << "Too high! Think lower.\n";
		}

		// if user guess is too low, do this code
		else if(userInput < randomNumber) 
		{
			cout << "Too low! Think higher.\n";
		}

		// if user guess is correct, do this code
		else 
		{    // display data to user, prompt if user wants to play again
			cout << "You got it, and it only took you " << numGuesses 
				        <<" trys!\nWould you like to play again (y/n)? ";
			cin >> playAgain;

			// if user wants to play again then re initialize the variables 
			if(playAgain == 'y'|| playAgain =='Y') 
			{
				// creates a line seperator if user wants to enter new data
				cout<<endl;
				cout.fill('-');
				cout<<left<<setw(30)<<""<<right<<setw(30)<<""<<endl;

				numGuesses = 0;
				cout << "\n\nMake a guess (between 1-1000):\n\n";
				// generate a new random number for the user to try & guess
				randomNumber = rand() % 1000+1;
			}
		}
	}while(playAgain =='y' || playAgain =='Y');
     // ^ do/while loop ends when user doesnt select 'Y' 

	// display data to user
	cout<<"\n\nThanks for playing!!"<<endl;
     
     return 0;
}// http://programmingnotes.org/
			
				
					
				
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						// ============================================================================
//    Author: Kenneth Perkins
//    Date:   Jan 20, 2012
//    Taken From: http://programmingnotes.org/
//    File:  guessingGame.cpp
//    Description: Demonstrates a simple random number guessing game
// ============================================================================
#include <iostream>
#include <ctime>
#include <iomanip>
using namespace std;
 
int main() 
{
	// declare & initialize variables
	char playAgain = 'y';
	int userInput = 0;
	int numGuesses = 0;
	// Seed the random number generator with the current time so
     // the numbers will be different every time the program runs
	srand(time(NULL));
	int randomNumber = rand() % 1000+1;
 
	// display directions to user
	cout << "I'm thinking of a number between 1 and 1000. Go ahead and make your first guess.\n\n";
 
	do{ // this is the start of the do/while loop
 
		// get data from user
		cin >> userInput;
		
		// increments the 'numGuesses' variable each time the user 
		// gets the guess wrong
		++numGuesses;
		
		// if user guess is too high, do this code
		if(userInput > randomNumber) 
		{
			cout << "Too high! Think lower.\n";
		}
 
		// if user guess is too low, do this code
		else if(userInput < randomNumber) 
		{
			cout << "Too low! Think higher.\n";
		}
 
		// if user guess is correct, do this code
		else 
		{    // display data to user, prompt if user wants to play again
			cout << "You got it, and it only took you " << numGuesses 
				        <<" trys!\nWould you like to play again (y/n)? ";
			cin >> playAgain;
 
			// if user wants to play again then re initialize the variables 
			if(playAgain == 'y'|| playAgain =='Y') 
			{
				// creates a line seperator if user wants to enter new data
				cout<<endl;
				cout.fill('-');
				cout<<left<<setw(30)<<""<<right<<setw(30)<<""<<endl;
 
				numGuesses = 0;
				cout << "\n\nMake a guess (between 1-1000):\n\n";
				// generate a new random number for the user to try & guess
				randomNumber = rand() % 1000+1;
			}
		}
	}while(playAgain =='y' || playAgain =='Y');
     // ^ do/while loop ends when user doesnt select 'Y' 
 
	// display data to user
	cout<<"\n\nThanks for playing!!"<<endl;
     
     return 0;
}// http://programmingnotes.org/

QUICK NOTES:
The highlighted lines are sections of interest to look out for.

The code is heavily commented, so no further insight is necessary. If you have any questions, feel free to leave a comment below.

Once compiled, you should get this as your output:

I'm thinking of a number between 1 and 1000. Go ahead and make your first guess.
67 Too low! Think higher. 500 Too low! Think higher. 700 Too high! Think lower. 600 Too low! Think higher. 680 Too high! Think lower. 650 Too low! Think higher. 660 Too low! Think higher. 670 You got it, and it only took you 8 trys! Would you like to play again (y/n)? y ------------------------------------------------------------ Make a guess (between 1-1000): 500 Too low! Think higher. 600 Too low! Think higher. 700 Too low! Think higher. 900 Too high! Think lower. 800 Too high! Think lower. 760 Too high! Think lower. 740 Too high! Think lower. 720 Too high! Think lower. 700 Too low! Think higher. 710 Too high! Think lower. 705 Too high! Think lower. 701 Too low! Think higher. 702 Too low! Think higher. 703 Too low! Think higher. 704 You got it, and it only took you 15 trys! Would you like to play again (y/n)? n
Thanks for playing!!

C++ || Find The Prime, Perfect & All Known Divisors Of A Number Using A For, While & Do/While Loop

January 11, 2012 admin No comments

This program was designed to better understand how to use different loops which are available in C++.

This program first asks the user to enter a non negative number. After it obtains a non negative integer from the user, the program will determine if the inputted number is a prime number or not, aswell as determine if the user inputted number is a perfect number or not. After it obtains its results, the program will display to the screen if the user inputted number is prime/perfect number or not. The program will also display a list of all the possible divisors of the user inputted number via cout.

REQUIRED KNOWLEDGE FOR THIS PROGRAM

Do/While Loop While Loop For Loop Modulus Basic Math - Prime Numbers Basic Math - Perfect Numbers Basic Math - Divisors





		
		
			Is It Prime or Perfect? List All Possible Divisors
			
C++
			
			#include <iostream>
#include <iomanip>
using namespace std;

int main ()
{
   int userInput = 0;
   int divisor = 0;
   int sumOfDivisors = 0;
   char response ='n';
   
   do{ // this is the start of the do/while loop
	   cout<<"Enter a number: ";
	   cin >> userInput;
	   
	   // if the user inputs a negative number, do this code
	   while(userInput < 0)  
	   {
		   cout<<"ntaSorry, but the number entered is less than the allowable limit. Please try again";
		   cout<<"nnEnter an number: ";
		   cin >> userInput;
	   }
	   
	   cout << "nInput number: " << userInput;

	   // for loop adds sum of all possible divisors
	   for(int counter=1; counter <= userInput; ++counter)
	   {
		   divisor = (userInput % counter);
		   if(divisor == 0)
		   {
			   // this will repeatedly add the found divisors together
			   sumOfDivisors += counter;
		   }
	   }
	   
	   // uses the 'sumOfDivisors' variable from ^ above for loop to 
	   // check if 'userInput' is prime
	   if(userInput == (sumOfDivisors - 1))
	   {
		   cout<<endl;
		   cout << userInput << " is a prime number.";
	   }
	   else
	   {
		   cout<<endl;
		   cout << userInput << " is not a prime number.";
	   }

	   // uses the 'sumOfDivisors' variable from ^ above for loop to 
	   // check if 'userInput' is a perfect number
	   if (userInput == (sumOfDivisors - userInput))
	   {
		   cout<<endl;
		   cout << userInput << " is a perfect number.";
	   }
	   else
	   {
		   cout<<endl;
		   cout << userInput << " is not a perfect number.";
	   }
	   
	   cout << "nDivisors of " << userInput << " are: ";

	   // for loop lists all the possible divisors for the
	   // 'userInput' variable by using the modulus operator
	   for(int counter=1; counter <= userInput; ++counter)
	   {
		   divisor = (userInput % counter);
		   if(divisor == 0 && counter !=userInput)
		   {
			   cout << counter << ", ";
		   }
	   }
	   cout << "and "<< userInput;
	   
	   // asks user if they want to enter new data
	   cout << "nntDo you want to input another number?(Y/N): ";
	   cin >> response;

	   // creates a line seperator if user wants to enter new data
	   cout.fill('-');
	   cout<<left<<setw(30)<<""<<right<<setw(30)<<""<<endl;

	   // resets variable back to zero if the user wants to enter new data
	   sumOfDivisors=0;
   }while(response =='y' || response =='Y');

   // ^ End of the do/while loop. As long as the user chooses
   // 'Y' the loop will keep going.
   // It stops when the user chooses the letter 'N'

   return 0;
}// http://programmingnotes.org/
			
				
					
				
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						#include <iostream>
#include <iomanip>
using namespace std;
 
int main ()
{
   int userInput = 0;
   int divisor = 0;
   int sumOfDivisors = 0;
   char response ='n';
   
   do{ // this is the start of the do/while loop
	   cout<<"Enter a number: ";
	   cin >> userInput;
	   
	   // if the user inputs a negative number, do this code
	   while(userInput < 0)  
	   {
		   cout<<"ntaSorry, but the number entered is less than the allowable limit. Please try again";
		   cout<<"nnEnter an number: ";
		   cin >> userInput;
	   }
	   
	   cout << "nInput number: " << userInput;
 
	   // for loop adds sum of all possible divisors
	   for(int counter=1; counter <= userInput; ++counter)
	   {
		   divisor = (userInput % counter);
		   if(divisor == 0)
		   {
			   // this will repeatedly add the found divisors together
			   sumOfDivisors += counter;
		   }
	   }
	   
	   // uses the 'sumOfDivisors' variable from ^ above for loop to 
	   // check if 'userInput' is prime
	   if(userInput == (sumOfDivisors - 1))
	   {
		   cout<<endl;
		   cout << userInput << " is a prime number.";
	   }
	   else
	   {
		   cout<<endl;
		   cout << userInput << " is not a prime number.";
	   }
 
	   // uses the 'sumOfDivisors' variable from ^ above for loop to 
	   // check if 'userInput' is a perfect number
	   if (userInput == (sumOfDivisors - userInput))
	   {
		   cout<<endl;
		   cout << userInput << " is a perfect number.";
	   }
	   else
	   {
		   cout<<endl;
		   cout << userInput << " is not a perfect number.";
	   }
	   
	   cout << "nDivisors of " << userInput << " are: ";
 
	   // for loop lists all the possible divisors for the
	   // 'userInput' variable by using the modulus operator
	   for(int counter=1; counter <= userInput; ++counter)
	   {
		   divisor = (userInput % counter);
		   if(divisor == 0 && counter !=userInput)
		   {
			   cout << counter << ", ";
		   }
	   }
	   cout << "and "<< userInput;
	   
	   // asks user if they want to enter new data
	   cout << "nntDo you want to input another number?(Y/N): ";
	   cin >> response;
 
	   // creates a line seperator if user wants to enter new data
	   cout.fill('-');
	   cout<<left<<setw(30)<<""<<right<<setw(30)<<""<<endl;
 
	   // resets variable back to zero if the user wants to enter new data
	   sumOfDivisors=0;
   }while(response =='y' || response =='Y');
 
   // ^ End of the do/while loop. As long as the user chooses
   // 'Y' the loop will keep going.
   // It stops when the user chooses the letter 'N'
 
   return 0;
}// http://programmingnotes.org/

QUICK NOTES:
The highlighted lines are sections of interest to look out for.

The code is heavily commented, so no further insight is necessary. If you have any questions, feel free to leave a comment below.

Once compiled, you should get this as your output:

Enter a number: 8128
Input number: 8128 8128 is not a prime number. 8128 is a perfect number. Divisors of 8128 are: 1, 2, 4, 8, 16, 32, 64, 127, 254, 508, 1016, 2032, 4064, and 8128 Do you want to input another number?(Y/N): y ------------------------------------------------------------ Enter a number: 6 Input number: 6 6 is not a prime number. 6 is a perfect number. Divisors of 6 are: 1, 2, 3, and 6 Do you want to input another number?(Y/N): y ------------------------------------------------------------ Enter a number: 241 Input number: 241 241 is a prime number. 241 is not a perfect number. Divisors of 241 are: 1, and 241 Do you want to input another number?(Y/N): y ------------------------------------------------------------ Enter a number: 2012 Input number: 2012 2012 is not a prime number. 2012 is not a perfect number. Divisors of 2012 are: 1, 2, 4, 503, 1006, and 2012
Do you want to input another number?(Y/N): n ------------------------------------------------------------ Press any key to continue . . .

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