I have written the following code to try to get my GPA calculator program to work. I am not allowed to use arrays. I only know what I am doing from the videos I have watched on youtube and the slideshows that we get from our instructor. Unfortunately, the slideshow this week does not cover using While and If statements.

Any help would be appreciated.

The goal of this is to find out the GPA of various courses.
Each course has a specific number of credit hours.
I am to prompt for a grade letter. The grade letter gets converted to a number letter, and then I am supposed to figure out the GPA.

// 

#include <iostream>
using namespace std;

void Error()
{
	cout << "Not a valid letter grade. Please check your letter grade and try again." << endl;
}

//need to find the grade point average for the semester

void main()
{
	float Sum = 0.00f;
	int Counter = 0;
	char LetterGrade = 0;
	float number = 0.00f;

//GetLetterGrade Module
	
	cout << "Enter Letter Grade: ";
	cin >> LetterGrade;

	while(LetterGrade != 0000)
	{
		Sum += LetterGrade;
		Counter += 1;
		cout << "Enter Letter Grade: ";
		cin >> number;
	}

//Convert Letter Grades to Numeric values
	switch(LetterGrade)
	   {
		
		case 'f':
		case 'F': number = 0.0;
			cout << "0.0";
			break;
		case 'd':
		case 'D': number = 1.0;
			break;
		case 'c':
		case 'C': number = 2.0;
			break;
		case 'b':
		case 'B': number = 3.0;
			break;
		case 'a':
		case 'A': number = 4.0;
			break;
		default: Error();
		      break;
	   }


	float Average = 0.00f;
	
//CalcAvgTemp Module    
	Average = Sum/Counter;

//PrintAvgTemp Module
	cout << "The Grade Point Average is " << Average << endl;
}

First off, I am not trying to become a programmer, so I will not be delving into the C++ world and with that I do not claim to know what I am doing. However, I do need to solve this problem.

So here is my problem solving method:

1. Identify the problem:
Create a program to identify the GPA for the semester.
2. Understand the problem:
Grades are given in letters
Convert the grades to numerical values (A=4.0, B=3.0, etc.,)
Grade point average is figured by units of credit
Example: History = B = 3 Units
have to use a trip value to stop the processing
have to use case structure to find the grade points.


The rest is algorithmic method, so i won;t post that here. But basically, I have the While command in there for the loop, but when I enter the second letter grade, my application goes into constant loop.

Second I am not sure how to "connect" the While statement with the Switch.

Your second input for Letter Grade wants to input into number (a float) rather than a character.

And what values do you expect to get with Sum += LetterGrade; when Sum is a float and LetterGrade is a character?

Second: put the switch statement inside the loop, with all the code needed to process each input.

Your second input for Letter Grade wants to input into number (a float) rather than a character.

So should I change the code to say Char number = 0

And what values do you expect to get with Sum += LetterGrade; when Sum is a float and LetterGrade is a character?

It worked for the other assignment that I did where we had to ad the sum of multiple values. I am not understanding how to get all of the entries to add up.

Second: put the switch statement inside the loop, with all the code needed to process each input.

I have no idea what this means.

program statements have to be written in logical sequence. For example you can not add LetterGrade to Sum before you know the value of LetterGrade. And LetterGrade has to be converted from A to F into numeric value befor it can be added to Sum.

char LetterGrade = 'A';
int number;
int Sum = 0;
while(LetterGrade != '0')
{
    cout << "Enter Letter Grade: ";
    cin >> LetterGrade;
    switch(LetterGrade)
    {
      case 'A': number = 100; break;
      // other case statements go here for each grade
    }
    Sum += number;
    Counter++;
}

I have made a few changes, broke out the modules and included your updated code (thank you very much Ancient Dragon)

Now the GPA, Sum, CreditHours are undeclared identifiers. Do I decalre them in Main?
Also, how do I get the CreditHours to add up? (guess this won;t matter until I declare the others)

#include <iostream>
using namespace std;

void GetLetterGrade();
void Error();
void CalcGPA();
void PrintGPA();

void main()
{

}

void GetLetterGrade()
{
	char LetterGrade = 'A';
	int CreditHours = 0;
	double Sum = 0;
	double number = 0;
	while(LetterGrade != 'E')
    {
		cout << "Enter Letter Grade: ";
		cin >> LetterGrade;
	
		cout << "Enter Credit Hours for this course: ";
		cin >> CreditHours;

		switch(LetterGrade)
	    {
		case 'a':
		case 'A': number = 4.0;
			break;
		case 'b':
		case 'B': number = 3.0;
			break;
		case 'c':
		case 'C': number = 2.0;
			break;
		case 'd':
		case 'D': number = 1.0;
			break;
		case 'f':
		case 'F': number = 0.0;
			break;
		default: Error();
		      break;
	    }
		Sum += number;
		
	}
}
void Error()
{
	cout << "Not a valid letter grade. Please check your letter grade and try again." << endl;
}

void CalcGPA()
{
	GPA = Sum/CreditHours;
}

void PrintGPA()
{
	cout << "The Grade Point Average is " << GPA << endl;
}

Or should I replace Sum in the CalcGPA() module with number?

replacing Sum didn;t work, I must be missing something in Main.

Okay, I have made some more changes, specifically removing the GetGradeLetter module and now I am able to compile the program (at leastwithout the calculation part anyway) and it is now accepting my Grade letter and Credit Horus, but the Credit Hours will need a reentry statement so i guess i will work on that, any help is still appreciated.

#include <iostream>
using namespace std;

int GetLetterGrade();
void Error();
void CalcGPA();
void PrintGPA();

void main()
{

    char LetterGrade = 'A';//value entered will be a character
	int CreditHours = 0;//value entered will be a whole number
	int Sum = 0;//value of sum will be a whole number
	int number = 0;//value of number will be a whole number
	
	cout << "Enter Letter Grade: " << endl ;
	cin >> LetterGrade;

	cout << "Enter Credit Hours for this course: " << endl;
	cin >> CreditHours;
	
	while(LetterGrade != 'E')//
    {
		
		cout << "Enter Letter Grade: " << endl;
		cin >> LetterGrade;
		
		switch(LetterGrade)
	    {
		case 'a':
		case 'A': number = 4;
			break;
		case 'b':
		case 'B': number = 3;
			break;
		case 'c':
		case 'C': number = 2;
			break;
		case 'd':
		case 'D': number = 1;
			break;
		case 'f':
		case 'F': number = 0;
			break;
		default: Error();
		      break;
	    }
	}
}
void Error()
{
	cout << "Not a valid letter grade. Please check your letter grade and try again." << endl;
}

/*void CalcGPA()
{
	GPA = Sum/CreditHours;
}

void PrintGPA()
{
	cout << "The Grade Point Average is " << GPA << endl;
}*/

Now I have a problem. I have added another While statement for the Credit Hours on the same level as GetGradeLevel and when my program Debugs I am asked for the Letter Grade. I hit enter and then it asks me for the Credit Hours. I enter credit hours and hit enter and then it constantly asks me for the credit hours. I was on a roll, but I am clueless at this point. How do I get the program to ask me the Grade Letter then the Credit hours, then the Grade Letter, then the Credit hours...all the while these are addign up in the background?

#include <iostream>
using namespace std;

int GetLetterGrade();
void Error();
void CalcGPA();
void PrintGPA();

void main()
{

    char LetterGrade = 'A';//value entered will be a character
	int CreditHours = 0;//value entered will be a whole number
	int Sum = 0;//value of sum will be a whole number
	int number = 0;//value of number will be a whole number
	
	cout << "Enter Letter Grade: " << endl ;
	cin >> LetterGrade;

	cout << "Enter Credit Hours for this course: " << endl;
	cin >> CreditHours;

	while(CreditHours != 0)
	{
		Sum += CreditHours;
		cout << "Enter Credit hours for this course: ";
		cin >> CreditHours;
	}

	while(LetterGrade != '0')//
    {
		
		cout << "Enter Letter Grade: " << endl;
		cin >> LetterGrade;
		
		switch(LetterGrade)
	    {
		case 'a':
		case 'A': number = 4;
			break;
		case 'b':
		case 'B': number = 3;
			break;
		case 'c':
		case 'C': number = 2;
			break;
		case 'd':
		case 'D': number = 1;
			break;
		case 'f':
		case 'F': number = 0;
			break;
		default: Error();
		      break;
	    }
	}
}
void Error()
{
	cout << "Not a valid letter grade. Please check your letter grade and try again." << endl;
}

/*void CalcGPA()
{
	GPA = Sum/CreditHours;
}

void PrintGPA()
{
	cout << "The Grade Point Average is " << GPA << endl;
}*/

Use some thing like that definitely it will work for you.
You want that program to ask user the Grade Letter then the Credit hours, then the Grade Letter, then the Credit hours...all the while these are addign up in the background?
Your problem is that your using two while 1st one for Credit hour and 2nd one for Grade letter which is worng you have to use a single while loop some thing like this

void main()
{

    char LetterGrade = 'A';//value entered will be a character
	int CreditHours = 0;//value entered will be a whole number
	int Sum = 0;//value of sum will be a whole number
	int number = 0;//value of number will be a whole number
	
	cout << "Enter Letter Grade: " << endl ;
	cin >> LetterGrade;

	cout << "Enter Credit Hours for this course: " << endl;
	cin >> CreditHours;

	while(CreditHours != 0 && LetterGrade != '0')
	{
		
		cout << "Enter Credit hours for this course: ";
		cin >> CreditHours;
	
		
		cout << "Enter Letter Grade: " << endl;
		cin >> LetterGrade;

		Sum += CreditHours;
		
		switch(LetterGrade)
	    {
		case 'a':
		case 'A': number = 4;
			break;
		case 'b':
		case 'B': number = 3;
			break;
		case 'c':
		case 'C': number = 2;
			break;
		case 'd':
		case 'D': number = 1;
			break;
		case 'f':
		case 'F': number = 0;
			break;
		default: Error();
		      break;
	    }
	}
}

how can we take -A as input of grade and assign them the grade points as 4.00
so that user input is -A,-B,B+ or any character with sing ....... and we calculate his/her GPA on the basis of these grades>>>???