Thread: Help Using Pointers

You probably want to pass sum and product to sum_product.

[edit]Don't use void main -- see the FAQ if you are tempted to ask why.

Code:

	printf("The sum is %d\n", &sum);
	printf("The product is %g\n", &product);

Remove the &'s, and use a floating-point format specifier for product.

Code:

void sum_product(int *x, int *y)
{		
	double *product =  (*x) * (*y);
	int *sum = *x+*y;
}

Here product and sum are pointers. They do not point to any valid memory that you can write to. Yet you go ahead and calculate a value and trample right over the memory that you can't write to by writing to it.

I would expect the function to be defined like this.

Code:

void sum_product(int *x, int *y, double *product, int *sum)

[edit]If you need to keep your prototype as is, you'll have to do your calculations and printing from within sum_product.

Do you have to use pointers for this problem or you can do it any other way? I really dont see why you would want to use pointers for such a simple problem. You can have 2 functions instead, 1 for the sum and 1 for the product to make your job easier and the program more readable. Here is a tip for you

Code:

#include <stdio.h>

int product(int num1, int num2);

int main()
{
	int num1;
	int num2;


	printf("Enter two integers: ");
	scanf("%d%d", &num1, &num2);
	
	printf("The # is %d and %d\n", num1, num2);
	printf("The product is %d\n",product(num1,num2));

}


int product(int num1, int num2)
{		
	return (num1 * num2);	
}

In that case you might want to read this http://faq.cprogramming.com/cgi-bin/...&id=1043284351 hope it helps you.

Been there already.

Originally Posted by Dave_Sinkula

Code:

	printf("The sum is %d\n", &sum);
	printf("The product is %g\n", &product);

Remove the &'s, and use a floating-point format specifier for product.

http://www.rt.com/man/printf.3.html

[edit]FAQ > How do I... (Level 1) > Format output using printf() (C)