C++ || Simple Multi Digit, Decimal & Negative Number Infix To Postfix Conversion & Evaluation The following is sample code which demonstrates the implementation of a multi digit, decimal, and negative number infix to postfix converter and evaluator using C++.

The program demonstrated on this page has the ability to convert and evaluate a single digit, multi digit, decimal number, and/or negative number infix equation. So for example, if the the infix equation of (19.87 * -2) was entered into the program, the converted postfix expression of 19.87 -2 * would display to the screen, as well as the final evaluated answer of -39.74.

REQUIRED KNOWLEDGE FOR THIS PROGRAM

How To Convert Infix To Postfix
How To Evaluate A Postfix Expression

1. Overview

The program demonstrated on this page is different from a previous implementation of the same type in that this version does not use a Finite State Machine during the conversion process, which simplifies the implemetation!

This program has the following flow of control:

• Get an infix expression from the user
• Convert the infix expression to postfix & isolate all of the math operators, multi digit, decimal, negative and single digit numbers that are found in the postfix expression
• Evaluate the postfix expression by breaking the infix string into tokens found from the above step
• Display the evaluated answer to the screen

The above steps are implemented below.

2. Infix To Posfix Conversion & Evaluation

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.

The following is sample output.

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

==== Infix To Postfix Conversion & Evaluation ====

Math Operators:
- || Subtraction
* || Multiplication
/ || Division
% || Modulus
^ || Power
\$ || Square Root
s || Sine
c || Cosine
t || Tangent
- || Negative Number
Sample Infix Equation: ((s(-4^5)*1.4)/(\$(23+2)--2.8))*(c(1%2)/(7.28*.1987)^(t23))

Please enter an Infix expression: 12/3*9

The Infix expression = 12/3*9
The Postfix expression = 12 3 / 9 *

Calculations:
12/3 = 4
4*9 = 36

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

==== Infix To Postfix Conversion & Evaluation ====

Math Operators:
- || Subtraction
* || Multiplication
/ || Division
% || Modulus
^ || Power
\$ || Square Root
s || Sine
c || Cosine
t || Tangent
- || Negative Number
Sample Infix Equation: ((s(-4^5)*1.4)/(\$(23+2)--2.8))*(c(1%2)/(7.28*.1987)^(t23))

Please enter an Infix expression: -150.89996 - 87.56643

The Infix expression = -150.89996 - 87.56643
The Postfix expression = -150.89996 87.56643 -

Calculations:
-150.9-87.5664 = -238.466

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

==== Infix To Postfix Conversion & Evaluation ====

Math Operators:
- || Subtraction
* || Multiplication
/ || Division
% || Modulus
^ || Power
\$ || Square Root
s || Sine
c || Cosine
t || Tangent
- || Negative Number
Sample Infix Equation: ((s(-4^5)*1.4)/(\$(23+2)--2.8))*(c(1%2)/(7.28*.1987)^(t23))

Please enter an Infix expression: ((s(-4^5)*1.4)/(\$(23+2)--2.8))*(c(1%2)/(7.28*.1987)^(t23))

The Infix expression = ((s(-4^5)*1.4)/(\$(23+2)--2.8))*(c(1%2)/(7.28*.1987)^(t23))
The Postfix expression = -4 5 ^ s 1.4 * 23 2 + \$ -2.8 - / 1 2 % c 7.28 .1987 * 23 t ^ / *

Calculations:
-4^5 = -1024
sin(-1024) = 0.158533
0.158533*1.4 = 0.221947
23+2 = 25
√25 = 5
5--2.8 = 7.8
0.221947/7.8 = 0.0284547
1%2 = 1
cos(1) = 0.540302
7.28*0.1987 = 1.44654
tan(23) = 1.58815
1.44654^1.58815 = 1.79733
0.540302/1.79733 = 0.300614
0.0284547*0.300614 = 0.00855389

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

==== Infix To Postfix Conversion & Evaluation ====

Math Operators:
- || Subtraction
* || Multiplication
/ || Division
% || Modulus
^ || Power
\$ || Square Root
s || Sine
c || Cosine
t || Tangent
- || Negative Number
Sample Infix Equation: ((s(-4^5)*1.4)/(\$(23+2)--2.8))*(c(1%2)/(7.28*.1987)^(t23))

Please enter an Infix expression: (1987 + 1991) * -1

The Infix expression = (1987 + 1991) * -1
The Postfix expression = 1987 1991 + -1 *

Calculations:
1987+1991 = 3978
3978*-1 = -3978

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

==== Infix To Postfix Conversion & Evaluation ====

Math Operators:
- || Subtraction
* || Multiplication
/ || Division
% || Modulus
^ || Power
\$ || Square Root
s || Sine
c || Cosine
t || Tangent
- || Negative Number
Sample Infix Equation: ((s(-4^5)*1.4)/(\$(23+2)--2.8))*(c(1%2)/(7.28*.1987)^(t23))

Please enter an Infix expression: (1+(2*((3+(4*5))*6)))

The Infix expression = (1+(2*((3+(4*5))*6)))
The Postfix expression = 1 2 3 4 5 * + 6 * * +

Calculations:
4*5 = 20
3+20 = 23
23*6 = 138
2*138 = 276
1+276 = 277

C++ || Multi Digit, Decimal & Negative Number Infix To Postfix Conversion & Evaluation The following is sample code which demonstrates the implementation of a multi digit, decimal, and negative number infix to postfix converter and evaluator using a Finite State Machine

REQUIRED KNOWLEDGE FOR THIS PROGRAM

How To Convert Infix To Postfix
How To Evaluate A Postfix Expression
What Is A Finite State Machine?

Using a Finite State Machine, the program demonstrated on this page has the ability to convert and evaluate a single digit, multi digit, decimal number, and/or negative number infix equation. So for example, if the the infix equation of (19.87 * -2) was entered into the program, the converted postfix expression of 19.87 ~2* would display to the screen, as well as the final evaluated answer of -39.74.

NOTE: In this program, negative numbers are represented by the “~” symbol on the postfix string. This is used to differentiate between a negative number and a subtraction symbol.

This program has the following flow of control:

• Get an infix expression from the user
• Convert the infix expression to postfix
• Use a Finite State Machine to isolate all of the math operators, multi digit, decimal, negative and single digit numbers that are found in the postfix expression
• Evaluate the postfix expression using the tokens found from the above step
• Display the evaluated answer to the screen

The above steps are implemented below.

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.

The following is sample output.

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

==== Infix To Postfix Conversion & Evaluation ====

Math Operators:
- || Subtraction
* || Multiplication
/ || Division
% || Modulus
^ || Power
\$ || Square Root
s || Sine
c || Cosine
t || Tangent
~ || Negative Number

Sample Infix Equation: ((s(~4^5)*1.4)/(\$(23+2)-~2.8))*(c(1%2)/(7.28*.1987)^(t23))

Please enter an Infix expression: 12/3*9

The Infix expression = 12/3*9
The Postfix expression = 12 3 /9*

Calculations:
12/3 = 4
4*9 = 36

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

==== Infix To Postfix Conversion & Evaluation ====

Math Operators:
- || Subtraction
* || Multiplication
/ || Division
% || Modulus
^ || Power
\$ || Square Root
s || Sine
c || Cosine
t || Tangent
~ || Negative Number

Sample Infix Equation: ((s(~4^5)*1.4)/(\$(23+2)-~2.8))*(c(1%2)/(7.28*.1987)^(t23))

Please enter an Infix expression: -150.89996 - 87.56643

The Infix expression = -150.89996 - 87.56643
The Postfix expression = ~150.89996 87.56643-

Calculations:
-150.9-87.5664 = -238.466

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

==== Infix To Postfix Conversion & Evaluation ====

Math Operators:
- || Subtraction
* || Multiplication
/ || Division
% || Modulus
^ || Power
\$ || Square Root
s || Sine
c || Cosine
t || Tangent
~ || Negative Number

Sample Infix Equation: ((s(~4^5)*1.4)/(\$(23+2)-~2.8))*(c(1%2)/(7.28*.1987)^(t23))

Please enter an Infix expression: ((s(~4^5)*1.4)/(\$(23+2)-~2.8))*(c(1%2)/(7.28*.1987)^(t23))

The Infix expression = ((s(-4^5)*1.4)/(\$(23+2)--2.8))*(c(1%2)/(7.28*.1987)^(t23))
The Postfix expression = ~4 5^ s1.4* 23 2+ \$~2.8-/ 1 2% c7.28 .1987* 23t^/*

Calculations:
-4^5 = -1024
sin(-1024) = 0.158533
0.158533*1.4 = 0.221947
23+2 = 25
√25 = 5
5--2.8 = 7.8
0.221947/7.8 = 0.0284547
1%2 = 1
cos(1) = 0.540302
7.28*0.1987 = 1.44654
tan(23) = 1.58815
1.44654^1.58815 = 1.79733
0.540302/1.79733 = 0.300614
0.0284547*0.300614 = 0.00855389

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

==== Infix To Postfix Conversion & Evaluation ====

Math Operators:
- || Subtraction
* || Multiplication
/ || Division
% || Modulus
^ || Power
\$ || Square Root
s || Sine
c || Cosine
t || Tangent
- || Negative Number
Sample Infix Equation: ((s(-4^5)*1.4)/(\$(23+2)--2.8))*(c(1%2)/(7.28*.1987)^(t23))

Please enter an Infix expression: (1987 + 1991) * -1

The Infix expression = (1987 + 1991) * -1
The Postfix expression = 1987 1991+ ~1*

Calculations:
1987+1991 = 3978
3978*-1 = -3978

Java || Snippet – How To Do Simple Math Using Integer Arrays This page will consist of simple programs which demonstrate the process of doing simple math with numbers that are stored in an integer array.

REQUIRED KNOWLEDGE FOR THIS SNIPPET

Integer Arrays
The "Random" Class
For Loops
Assignment Operators - Simple Math Operations
Custom Setw/Setfill In Java

Note: In all of the examples on this page, a random number generator was used to place numbers into the array. If you do not know how to obtain data from the user, or if you do not know how to insert data into an array, click here for a demonstration.

The first code snippet will demonstrate how to add numbers together which are stored in an integer array. This example uses the “+=” assignment operator.

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.

SAMPLE OUTPUT

Welcome to My Programming Notes' Java Program.

Original array values:
22 26 41 89 35 90 15 99 85 5 95 86
--------------------------------------------------
The sum of the items in the array is: 688

===== SUBTRACTION =====

The second code snippet will demonstrate how to subtract numbers which are stored in an integer array. This example uses the “-=” assignment operator.

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.

SAMPLE OUTPUT

Welcome to My Programming Notes' Java Program.

Original array values:
99 92 91 26 1 52 98 62 51 22 64 65
--------------------------------------------------
The difference of the items in the array is: -723

===== MULTIPLICATION =====

The third code snippet will demonstrate how to multiply numbers which are stored in an integer array. This example uses the “*=” assignment operator.

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.

SAMPLE OUTPUT

Welcome to My Programming Notes' Java Program.

Original array values:
95 63 32 19 93 83 71 35 32 37 66 95
--------------------------------------------------
The product of the items in the array is: 494770176

===== DIVISION =====

The fourth code snippet will demonstrate how to divide numbers which are stored in an integer array. This example uses the “/=” assignment operator.

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.

SAMPLE OUTPUT

Welcome to My Programming Notes' Java Program.

Original array values:
28 85 90 52 1 64 93 85 4 22 4 28
--------------------------------------------------
The quotient of the items in the array is: 1.8005063061510687E-17

Java || Snippet – How To Find The Highest & Lowest Numbers Contained In An Integer Array This page will consist of a simple demonstration for finding the highest and lowest numbers contained in an integer array.

REQUIRED KNOWLEDGE FOR THIS SNIPPET

Integer Arrays
For Loops
Custom Setw/Setfill In Java

Finding the highest/lowest values in an array can be found in one or two ways. The first way would be via a sort, which would obviously render the highest/lowest numbers contained in the array because the values would be sorted in order from highest to lowest. But a sort may not always be practical, especially when you want to keep the array values in the same order that they originally came in.

The second method of finding the highest/lowest values is by traversing through the array, literally checking each value it contains one by one to determine if the current number which is being compared truly is a target value or not. That method will be displayed below.

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.

Original array values:
36 35 46 86 86 58 44 38 79 52 27 78 65 79
------------------------------------------------------------
These are the highest and lowest array values:
Highest: 86
Lowest: 27

Java || Snippet – How To Input Numbers Into An Integer Array & Display Its Contents Back To User This snippet demonstrates how to place numbers into an integer array. It also shows how to display the contents of the array back to the user via stdout.

REQUIRED KNOWLEDGE FOR THIS SNIPPET

Integer Arrays
For Loops
Final Variables

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.

How many items do you want to place into the array?: 5

Enter item #1: 12
Enter item #2: 43
Enter item #3: 5
Enter item #4: 643
Enter item #5: 2321

The current items inside the array are:
Item #1: 12
Item #2: 43
Item #3: 5
Item #4: 643
Item #5: 2321

C++ || Convert Numbers To Words Using A Switch Statement This program demonstrates more practice using arrays and switch statements.

REQUIRED KNOWLEDGE FOR THIS PROGRAM

Integer Arrays
Cin.get
Isdigit
For loops
While Loops
Switch Statements - How To Use

Using “cin.get(),” this program first asks the user to enter in a number (one at a time) that they wish to translate into words. If the text which was entered into the system is a number, the program will save the user input into an integer array. If the text is not a number, the input is discarded. After integer data is obtained, a for loop is used to traverse the integer array, passing the data to a switch statement, which translates the number to text.

This program is very simple, so it does not have the ability to display any number prefixes. As a result, if the number “1858” was entered into the system, the program would output the converted text: “One Eight Five Eight.”

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 four separate times to display different output

======= Run #1 =======

Enter number: 77331

Seven Seven Three Three One

======= Run #2 =======

Enter number: 234-43-1275

Two Three Four Four Three One Two Seven Five

======= Run #3 =======

Enter number: 1(800) 123-5678

One Eight Zero Zero One Two Three Five Six Seven Eight

======= Run #4 =======

Enter number: This 34 Is 24 A 5 Number 28

Three Four Two Four Five Two Eight

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

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 || Searching An Integer Array For A Target Value Here is another actual homework assignment which was presented in an intro to programming class which was used to introduce more practice using integer arrays.

REQUIRED KNOWLEDGE FOR THIS PROGRAM

Integer Arrays
For Loops
Methods (A.K.A "Functions") - What Are They?
Final Variables
If/Else Statements

This is a small and simple program which demonstrates how to search for a target value which is stored in an integer array. This program first prompts the user to enter five values into an int array. After the user enters all the values into the system, it then displays a prompt asking the user for a search value. Once it has a search value, the program searches through the array looking for the target value; and wherever the value is found, the program display’s the current array index in which that target value is located. After it displays all the locations where the target value resides, it display’s the total number of occurrences the search value was found within the array.

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 the different outputs its able to produce

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

Welcome to My Programming Notes' Java Program.

#1: 25
#2: 25
#3: 25
#4: 25
#5: 25
Please enter a search value: 25

25 was found at array index #0
25 was found at array index #1
25 was found at array index #2
25 was found at array index #3
25 was found at array index #4

The total occurrences of value 25 within the array is: 5

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

Welcome to My Programming Notes' Java Program.

#1: 8
#2: 19
#3: 97
#4: 56
#5: 8
Please enter a search value: 8

8 was found at array index #0
8 was found at array index #4

The total occurrences of value 8 within the array is: 2

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

Welcome to My Programming Notes' Java Program.

#1: 78
#2: 65
#3: 3
#4: 45
#5: 89
Please enter a search value: 12

The total occurrences of value 12 within the array is: 0

Java || Find The Average Using an Array – Omit Highest And Lowest Scores This page will consist of two programs which calculates the average of a specific amount of numbers using an array.

REQUIRED KNOWLEDGE FOR BOTH PROGRAMS

Double Data Type
Final Variables
Arrays
For Loops
Assignment Operators
Basic Math - How To Find The Average

====== FIND THE AVERAGE USING AN ARRAY ======

The first program is fairly simple, and it was used to introduce the array concept. The program prompts the user to enter the total amount of numbers they want to find the average for, then the program displays the answer to them via stdout.

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

ARRAY
Notice the array declaration on line #13. The type of array being used in this program is a dynamic array, which has the ability to store up to 100 integer elements in the array. You can change the number of elements its able to store to a higher or lower number if you wish.

FOR LOOP
Lines 27-32 contains a for loop, which is used to actually store the data inside of the array. Without some type of loop, it is virtually impossible for the user to input data into the array; that is, unless you want to add 100 different println statements into your code asking the user to input data. Line 31 uses the assignment operator “+=” which gives us a running total of the data that is being inputted into the array. Note the loop only stores as many elements as the user so desires, so if the user only wants to input 3 numbers into the array, the for loop will only execute 3 times.

Once compiled, you should get this as your output:

Welcome to My Programming Notes' Java Program.

How many numbers do you want to find the average for?: 4
Enter value #1: 21
Enter value #2: 24
Enter value #3: 19
Enter value #4: 17
The average of the 4 numbers is 20.25

====== FIND THE AVERAGE – OMIT HIGHEST AND LOWEST SCORES ======

The second program is really practical in a real world setting. We were asked to create a program for a fictional competition which had 6 judges. The 6 judges each gave a score of the performance for a competitor in a competition, (i.e a score of 1-10), and we were asked to find the average of those scores, omitting the highest/lowest results. The program was to store the scores into an array, display the scores back to the user via stdout, display the highest and lowest scores among the 6 obtained, display the average of the 6 scores, and finally display the average adjusted scores omitting the highest and lowest result.

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

FINAL
A final variable was declared and used to initialize the array (line 7). This was used to initialize the size of the array.

FOR LOOPS
Once again loops were used to traverse the array, as noted on lines 24, 51 and 73. The final variable was also used within the for loops, making it easier to modify the code if its necessary to reduce or increase the number of available judges.

HIGHEST/LOWEST SCORES
This is noted on lines 35-45, and it is really simple to understand the process once you see the code.

OMITTING HIGHEST/LOWEST SCORE
Lines 73-81 highlights this process. The loop basically traverses the array, skipping over the highest/lowest elements.

Once compiled, you should get this as your output

Welcome to My Programming Notes' Java Program.

Judges, enter one score each for
the current competitor: 123 453 -789 2 23345 987

These are the scores from the 6 judges:
The score for judge #1 is: 123.0
The score for judge #2 is: 453.0
The score for judge #3 is: -789.0
The score for judge #4 is: 2.0
The score for judge #5 is: 23345.0
The score for judge #6 is: 987.0

These are the highest and lowest scores:
Highest: 23345.0
Lowest: -789.0
The average score is: 4020.1666666666665
The average adjusted score omitting the highest and lowest result is: 391.25

C++ || Char Array – Determine If A String Is A Number Or Not The following is another intermediate homework assignment which was presented in a C++ programming course. This program was assigned to introduce more practice using and manipulating character arrays.

REQUIRED KNOWLEDGE FOR THIS PROGRAM

Character Arrays
Cin.getline
Strlen - Get The Length Of A Char Array
Isalpha
Isspace

This program first prompts the user to input a line of text. After it obtains data from the user, using a for loop, it then displays the the string to the screen one letter (char) at a time. If the current character at that specific array index is a letter, a “flag” is set, indicating that the current word which is being displayed is not a number. If the “flag” is not set, the current word is indeed a number.

This program has the ability to intake multiple words at a time, so for example, if the user input was “Hello World 2012” the program would display the output:

Hello is NOT a number!
World is NOT a number!
2012 is a number..

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 three separate times to display different output)

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

Enter some text to see if its a number or not: My Programming Notes

My is NOT a number! There are 2 letters in that word...
Programming is NOT a number! There are 11 letters in that word...
Notes is NOT a number! There are 5 letters in that word...

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

Enter some text to see if its a number or not: May 30th 2012

May is NOT a number! There are 3 letters in that word...
30th is NOT a number! There are 2 letters in that word...
2012 is a number..

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

Enter some text to see if its a number or not: 5 31 2012

5 is a number..
31 is a number..
2012 is a number..

C++ || Stack – Using A Stack, Determine If A Set Of Parentheses Is Well-Formed Here is another homework assignment which was presented in a C++ Data Structures course. This assignment was used to introduce the stack ADT, and helped prepare our class for two later assignments which required using a stack. Those assignments can be found here:

(1) Stack Based Infix To Postfix Conversion (Single Digit)
(2) Stack Based Postfix Evaluation (Single Digit)

REQUIRED KNOWLEDGE FOR THIS PROGRAM

Stack Data Structure
Cin.getline
#include "ClassStackListType.h"

A simple exercise for testing a stack is determining whether a set of parenthesis is “well formed” or not. What exactly is meant by that? In the case of a pair of parenthesis, for an expression to be well formed, consider the following table.

Given an expression with characters and parenthesis, ( ), [ ], and { }, our class was asked to determine if an expression was well formed or not by using the following algorithm:

======= WELL-FORMED EXPRESSIONS =======

This program uses a custom template.h class. To obtain the code for that class, click here.

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 compile four separate times to display different output)

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

Enter an expression and press ENTER.
((
The expression: (( is NOT well formed!!!

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

Enter an expression and press ENTER.
(a{b[]}c)

The expression: (a{b[]}c) is well formed...

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

Enter an expression and press ENTER.
[(7 * 28) - 1987]

The expression: [(7 * 28) - 1987] is well formed...

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

Enter an expression and press ENTER.
{3 + [2 / 3] - (9 + 18) * 12)

The expression: {3 + [2 / 3] - (9 + 18) * 12) is NOT well formed!!!

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

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

root 1 = 2
root 2 = -4

Press ENTER to continue...

C++ || Class & Input/Output – Display The Contents Of A User Specified Text File To The Screen The following is another intermediate homework assignment which was presented in a C++ programming course. This program was assigned to introduce more practice using 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?
How To Read Data From A File
String - Getline
Array - Cin.Getline
Strcpy - Copy Contents Of An Array
#Define

This program first prompts the user to input a file name. After it obtains a file name from the user, it then attempts to display the contents of the user specified file to the output screen. If the file could not be found, an error message appears. If the file is found, the program continues as normal. After the file contents finishes being displayed, a summary indicating the total number of lines which has been read is also shown to the screen.

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).

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]

======== FILE #1 – Main.cpp ========

======== FILE #2 – CFileDisp.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 #3 – CFileDisp.cpp ========

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