Tag Archives: string

Python || Using If Statements & String Variables

As previously mentioned, you can use “int” and “float” to represent numbers, but what if you want to store letters? Strings help you do that.

==== SINGLE CHAR ====

This example will demonstrate a simple program using strings, which checks to see if the user entered the correctly predefined letter.


Notice in line 3 I declare the char data type, naming it “userInput.” I also initialized it as an empty variable. In line 15 I used an “If/Else Statement” to determine if the user entered value matches the predefined letter within the program. I also used the “OR” operator in line 15 to determine if the letter the user entered into the program was lower or uppercase. Try compiling the program simply using this
if (letter == 'a') as your if statement, and notice the difference.

The resulting code should give this as output

Please try to guess the letter I am thinking of: A
You have guessed correctly!

==== CHECK IF LETTER IS UPPER CASE ====

This example is similar to the previous one, and will check if a user entered letter is uppercase.


Notice in line 13, an If statement was used, which checkes to see if the user entered data falls between letter A and letter Z. We did that by using the “AND” operator. So that IF statement is basically saying (in plain english)

IF ('letter' is equal to or greater than 'A') AND ('letter' is equal to or less than 'Z')

THEN it is an uppercase letter

The resulting code should give this as output

Please enter an UPPERCASE letter: g
Sorry, 'g' is not an uppercase letter..

==== CHECK IF LETTER IS A VOWEL ====

This example will utilize more if statements, checking to see if the user entered letter is a vowel or not. This will be very similar to the previous example, utilizing the OR operator once again.


This program should be very straight forward, and its basically checking to see if the user entered data is the letter A, E, I, O, U or Y.

The resulting code should give the following output

Please enter a vowel: K
Sorry, 'K' is not a vowel..

==== HELLO WORLD v2 ====

This last example will demonstrate using the string data type to print the line “Hello World!” to the screen.


The following is similar to the other examples listed on this page, except we display the entire string instead of just simply the first character.

The resulting code should give following output

Please enter a sentence: Hello World!
You Entered: 'Hello World!'

C++ || Snippet – How To Convert A Decimal Number Into Binary

This page will demonstrate how to convert a decimal number (i.e a whole number) into its binary equivalent. So for example, if the decimal number of 26 was entered into the program, it would display the converted binary value of 11010.

REQUIRED KNOWLEDGE FOR THIS SNIPPET

How To Count In Binary
The "Long" Datatype - What Is It?
While Loops
Online Binary to Decimal Converter - Verify For Correct Results
How To Reverse A String

If you are looking for sample code which converts binary to decimal, check back here soon!


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
Note: The code was compiled 3 separate times to display different output

====== RUN 1 ======

Please enter an integer value: 1987

The integer value of 1987 = 11111000011 in binary

====== RUN 2 ======

Please enter an integer value: -26

The integer value of -26 = -11010 in binary

====== RUN 3 ======

Please enter an integer value: 12345678910

The integer value of 12345678910 = 1011011111110111000001110000111110 in binary

Java || Snippet – How To Convert A Decimal Number Into Binary

This page will demonstrate how to convert a decimal number (i.e a whole number) into its binary equivalent. So for example, if the decimal number of 25 was entered into the program, it would display the converted binary value of 11001.

REQUIRED KNOWLEDGE FOR THIS SNIPPET

How To Count In Binary
The "Long" Datatype - What Is It?
Methods (A.K.A "Functions") - What Are They?
While Loops
Online Binary to Decimal Converter - Verify For Correct Results

If you are looking for sample code which converts binary to decimal, check back here soon!


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
Note: The code was compiled 3 separate times to display different output

====== RUN 1 ======

Welcome to My Programming Notes' Java Program.

Please enter an integer value: 5

The integer value of 5 = 101 in binary

====== RUN 2 ======

Welcome to My Programming Notes' Java Program.

Please enter an integer value: -25

The integer value of -25 = -11001 in binary

====== RUN 3 ======

Welcome to My Programming Notes' Java Program.

Please enter an integer value: 12345678910

The integer value of 12345678910 = 1011011111110111000001110000111110 in binary

Java || Whats My Name? – Practice Using Strings, Methods & Switch Statemens

Here is another actual homework assignment which was presented in an intro to programming class. This program highlights more use using strings, modules, and switch statements.

REQUIRED KNOWLEDGE FOR THIS PROGRAM

How To Get String Input
If/Else Statements
Methods (A.K.A "Functions") - What Are They?
Switch Statements - How To Use Them
Equal - String Comparison

This program first prompts the user to enter their name. Upon receiving that information, the program saves input into a string called “firstName.” The program then asks if the user has a middle name. If they do, the user will enter a middle name. If they dont, the program proceeds to ask for a last name. Upon receiving the first, [middle], and last names, the program will append the first, [middle], and last names into a completely new string titled “fullName.” Lastly, if the users’ first, [middle], or last names are the same, the program will display that data to the screen via stdout. The program will also display to the user the number of characters their full name contains using the built in function “length.”


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
Note: The code was compiled five separate times to display the different outputs its able to produce

====== RUN 1 ======

Welcome to My Programming Notes' Java Program.

Please enter your first name: My
Do you have a middle name?(Y/N): y
Please enter your middle name: Programming
Please enter your last name: Notes

The total number of characters in your name is: 18
And your full name is My Programming Notes

====== RUN 2 ======

Welcome to My Programming Notes' Java Program.

Please enter your first name: Programming
Do you have a middle name?(Y/N): n
Please enter your last name: Notes

The total number of characters in your name is: 16
And your full name is Programming Notes

====== RUN 3 ======

Welcome to My Programming Notes' Java Program.

Please enter your first name: Notes
Do you have a middle name?(Y/N): y
Please enter your middle name: Notes
Please enter your last name: Notes

Your first and middle name are the same
Your middle and last name are the same
Your first and last name are the same

The total number of characters in your name is: 15
And your full name is Notes Notes Notes

====== RUN 4 ======

Welcome to My Programming Notes' Java Program.

Please enter your first name: My
Do you have a middle name?(Y/N): n
Please enter your last name: My

Your first and last name are the same

The total number of characters in your name is: 4
And your full name is My My

====== RUN 5 ======

Welcome to My Programming Notes' Java Program.

Please enter your first name: My
Do you have a middle name?(Y/N): z

Please press either 'Y' or 'N'
Program exiting...

Java || Count The Total Number Of Characters, Vowels, & UPPERCASE Letters Contained In A Sentence Using A ‘For Loop’

Here is a simple program, which demonstrates more practice using the input/output mechanisms which are available in Java.

This program will prompt the user to enter a sentence, then upon entering an “exit code,” will display the total number of uppercase letters, vowels and characters which are contained within that sentence. This program is very similar to an earlier project, this time, utilizing a for loop, strings, and user defined methods.

REQUIRED KNOWLEDGE FOR THIS PROGRAM

How To Get String Input
If/Else Statements
For Loops
Methods (A.K.A "Functions") - What Are They?


QUICK NOTES:
The highlighted portions are areas of interest.

Notice line 22 contains the for loop declaration. The loop will continually loop thru the string, and will not stop doing so until it reaches an exit character, and the defined exit character in this program is a period (“.”). So, the program will not stop looping thru the string until it reaches a period.

Once compiling the above code, you should receive this as your output

Welcome to My Programming Notes' Java Program.

Enter a sentence, ending with a period:
My Programming Notes Is An Awesome Site.

Total number of upper case letters:........7
Total number of vowels:....................14
Total number of characters:................33

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

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


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++ || Snippet – How To Read & Write Data From A User Specified Text File

This page will consist of a demonstration of a simple quadratic formula program, which highlights the use of the input/output mechanisms of manipulating a text file. This program is very similar to an earlier snippet which was presented on this site, but in this example, the user has the option of choosing which file they want to manipulate. This program also demonstrates how to read in data from a file (numbers), manipulate that data, and output new data into a different text file.

REQUIRED KNOWLEDGE FOR THIS SNIPPET

Fstream
Ifstream
Ofstream
Working With Files
C_str() - Convert A String To Char Array Equivalent
Getline - String Version

Note: The data file that is used in this example can be downloaded here.

Also, in order to read in the data .txt file, you need to save the .txt file in the same directory (or folder) as your .cpp file is saved in. If you are using Visual C++, this directory will be located in

Documents > Visual Studio 2010 > Projects > [Your project name] > [Your project name]


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

Please enter the name of the file: INPUT_Quadratic_programmingnotes_freeweq_com.txt

For the numbers
a = 2
b = 4
c = -16

root 1 = 2
root 2 = -4

Press ENTER to continue...

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

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)


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 #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 #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”


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!

Java || Using If Statements, Char & String Variables

As previously mentioned, you can use the “int/float/double” data type to store numbers. But what if you want to store letters? Char and Strings help you do that.

===== SINGLE CHAR =====

This example will demonstrate a simple program using char, which checks to see if you inputted the correctly predefined letter


Notice in line 11 I declare the char data type, naming it “userInput.” I also initialized it as an empty variable. In line 18 I used an “If/Else Statement” to determine if the user inputted value matches the predefined letter within the program. I also used the “OR” operator in line 18 to determine if the letter the user inputted was lower or uppercase. Try compiling the program simply using this
if (userInput == 'a') as your if statement, and notice the difference.

The resulting code should give this as output

Please try to guess the letter I am thinking of: A
You have Guessed correctly!

===== CHECK IF LETTER IS UPPER CASE =====

This example is similar to the previous one, and will check if a letter is uppercase


Notice in line 18, an If statement was used, which checked to see if the user inputted data fell between letter A and letter Z. We did that by using the “AND” operator. So that IF statement is basically saying (in plain english)

IF ('userInput' is equal to or greater than 'A') AND ('userInput' is equal to or less than 'Z')

THEN it is an uppercase letter

The resulting code should give this as output

Please enter an UPPERCASE letter: p
p is not an uppercase letter

===== CHECK IF LETTER IS A VOWEL =====

This example will utilize more if statements, checking to see if the user inputted data is a vowel or not. This will be very similar to the previous example, utilizing the OR operator once again.


This program should be very straight forward, and its basically checking to see if the user inputted data is the letter A, E, I, O, U or Y.

The resulting code should give the following output

Please enter a vowel: o
Correct, o is a vowel!

===== HELLO WORLD v2 =====

This last example will demonstrate using the string data type to print the line “Hello World!” to the screen.


The resulting code should give following output

Please enter a sentence: Hello World!
You entered: Hello World!

===== HOW TO COMPILE CODE USING THE TERMINAL =====

*** This can be achieved by typing the following command:
(Notice the .java source file is named exactly the same as the class header)

javac YOUR_CLASS_NAME.java

*** To run the compiled program, simply type this command:

java YOUR_CLASS_NAME

C++ || Find The Day Of The Week You Were Born Using Functions, String, Modulus, If/Else, & Switch

This program displays more practice using functions, modulus, if and switch statements.

REQUIRED KNOWLEDGE FOR THIS PROGRAM

Functions
Strings
Modulus
If/Else Statements
Switch Statements
Knowledge of Leap Years
A Calendar

This program prompts the user for their name, date of birth (month, day, year), and then displays information back to them via cout. Once the program obtains selected information from the user, it will use simple math to determine the day of the week in which the user was born, and determine the day of the week their current birthday will be for the current calendar year. The program will also display to the user their current age, along with re-displaying their name back to them.

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


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:
Note: The code was compiled five separate times to display the different outputs its able to produce

Please enter your name: MyProgrammingNotes
Please enter the month in which you were born (between 1 and 12): 1
Please enter the day you were born (between 1 and 31): 1
Please enter the year you were born (between 1900 and 2099): 2012

Hello MyProgrammingNotes. Here are some facts about you!
You were born January 1 2012
Your birth took place on a Sunday
This year your birthday will take place on a Sunday
You currently are, or will be 0 years old this year!
---------------------------------------------------------------------

Please enter your name: Name
Please enter the month in which you were born (between 1 and 12): 4
Please enter the day you were born (between 1 and 31): 2
Please enter the year you were born (between 1900 and 2099): 1957

Hello Name. Here are some facts about you!
You were born April 2 1957
Your birth took place on a Tuesday
This year your birthday will take place on a Monday
You currently are, or will be 55 years old this year!
---------------------------------------------------------------------

Please enter your name: Name
Please enter the month in which you were born (between 1 and 12): 5
Please enter the day you were born (between 1 and 31): 7
Please enter the year you were born (between 1900 and 2099): 1999

Hello Name. Here are some facts about you!
You were born May 7 1999
Your birth took place on a Friday
This year your birthday will take place on a Monday
You currently are, or will be 13 years old this year!
---------------------------------------------------------------------

Please enter your name: Name
Please enter the month in which you were born (between 1 and 12): 8
Please enter the day you were born (between 1 and 31): 4
Please enter the year you were born (between 1900 and 2099): 1983

Hello Name. Here are some facts about you!
You were born August 4 1983
Your birth took place on a Thursday
This year your birthday will take place on a Saturday
You currently are, or will be 29 years old this year!
---------------------------------------------------------------------

Please enter your name: Name
Please enter the month in which you were born (between 1 and 12): 6
Please enter the day you were born (between 1 and 31): 7
Please enter the year you were born (between 1900 and 2099): 2987

You have entered an invalid year. Please enter a valid year.
Press any key to continue . . .

C++ || Using If Statements, Char & String Variables

As previously mentioned, you can use the “int/float/double” data type to store numbers. But what if you want to store letters? Char and Strings help you do that.

==== SINGLE CHAR ====

This example will demonstrate a simple program using char, which checks to see if you inputted the correctly predefined letter


Notice in line 6 I declare the char data type, naming it “userInput.” I also initialized it as an empty variable. In line 12 I used an “If/Else Statement” to determine if the user inputted value matches the predefined letter within the program. I also used the “OR” operator in line 12 to determine if the letter the user inputted was lower or uppercase. Try compiling the program simply using this
if (userInput == 'a') as your if statement, and notice the difference.

The resulting code should give this as output

Please try to guess the letter I am thinking of: K
Sorry, that was not the correct letter I was thinking of

==== CHECK IF LETTER IS UPPER CASE ====

This example is similar to the previous one, and will check if a letter is uppercase


Notice in line 12, an If statement was used, which checked to see if the user inputted data fell between letter A and letter Z. We did that by using the “AND” operator. So that IF statement is basically saying (in plain english)

IF ('userInput' is equal to or greater than 'A') AND ('userInput' is equal to or less than 'Z')

THEN it is an uppercase letter

C++ uses ASCII codes to determine letters, so from looking at the table, the letter ‘A’ would equal ASCII code number 65, letter ‘B’ would equal ASCII code number 66 and so forth, until you reach letter Z, which would equal ASCII code number 90. So in literal terms, the program is checking to see if the user input is between ASCII code number 65 thru 90. If it is, then the number is an uppercase letter, otherwise it is not.

The resulting code should give this as output

Please enter an UPPERCASE letter: G
G is an uppercase letter


==== CHECK IF LETTER IS A VOWEL ====

This example will utilize more if statements, checking to see if the user inputted data is a vowel or not. This will be very similar to the previous example, utilizing the OR operator once again.


This program should be very straight forward, and its basically checking to see if the user inputted data is the letter A, E, I, O, U or Y.

The resulting code should give the following output

Please enter a vowel: O
Correct, O is a vowel!

==== HELLO WORLD v2 ====

This last example will demonstrate using the string data type to print the line “Hello World!” to the screen.


Notice in line 2 we have to add “#include string” in order to use the getline function, which is used on line 10. Rather than just simply using the “cin” function, we used the getline function instead to read in data. That is because cin is unable to read entire sentences as input. So in line 10, the following code reads a line from the user input until a newline is entered.

The resulting code should give following output

Please enter a sentence: Hello World!
You Entered: Hello World!