Thread: adding contents of an array

I have this program i'm working on and i'm suppose to input some grade averages and then calculate the avg what I'm trying to do first is just add all the GPAs but it won't work can someone tell me why heres the code

Code:

#include <stdio.h>
#include <stdlib.h>

void CalculateAvg(void);

int i;
float iGpa[] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0};


int main()
{
	int iChoice = 0;

	while (iChoice != 3)
	{
		printf("\n\tGPA Calculator\n");
		printf("1\tCalculate Average\n");
		printf("2\tEnter new GPA\n");
		printf("3\tQuit\n");

		printf("\n\n\tEnter a choice: ");
		scanf("%d",&iChoice);

		if(iChoice == 1)
		{
			system("cls");
			CalculateAvg();
		}



		if(iChoice == 2)
		{
			printf("\n\tGPA Calculator\n");
			printf("\tEnter a GPA: ");
			scanf("%f",&iGpa[i]);
		}

		
	}
}
void CalculateAvg()
{
	float x;
	int i;
	for (i = 0; i <= 30; i++)
		x += iGpa[i];
	printf("The average is %f\n",x);
}

Initialize x doesn't do the trick it comes out the same what it does is print the last record I entered

You need to initialize x, for sure, to 0.0

Then you need to divide x after you've added up the grades into it, by the number of grades in iGpa. After all, it's still calculating an average.

but it won't add up the grades the code is wrong or something it prints out the last GPA record I put in there not them all added up that's what I don't get

if I can't add them then I can't divide them

And here's the answer to that:

scanf("%f",&iGpa[i]);

You want i++ in there, not just i, and you need to initialize it to 0, also.

hey thanks guys I ran the code it works now here it is

Code:

#include <stdio.h>
#include <stdlib.h>

void CalculateAvg(void);

int iNum = 0;
float iGpa[] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0};

int main()
{
	int i = 0;
	int iChoice = 0;

	printf("\n\tGPA Calculator\n");
	printf("\tHow many records to enter: ");
	scanf("%d",&iNum);


	while (iChoice != 3)
	{
		printf("\n\tGPA Calculator\n");
		printf("1\tCalculate Average\n");
		printf("2\tEnter new GPA\n");
		printf("3\tQuit\n");

		printf("\n\n\tEnter a choice: ");
		scanf("%d",&iChoice);

		if(iChoice == 1)
		{
			system("cls");
			CalculateAvg();
		}



		if(iChoice == 2)
		{
			printf("\n\tGPA Calculator\n");
			printf("\tEnter a GPA: ");
			scanf("%f",&iGpa[i++]);
		}

		
	}
}
void CalculateAvg()
{
	float x = 0;
	int i;
	for (i = 0; i <= iNum; i++)
		x += iGpa[i];
	printf("The average is %f\n",x/iNum);
}