Swap Two Numbers Using Pointers

Here is the code for swapping two numbers using a function which is based on pointers. The basic concept used is pass by reference.

Code

#include <stdio.h>

void swap(int *x, int *y)
{
    int tmp;

    tmp  = *y;
    *y   = *x;
    *x   = tmp;
}

int main()
{
    int a, b;

    printf("Enter two numbers: ");
    scanf("%d%d", &a, &b);

    printf("\nBefore swapping: a = %d and b = %d\n", a, b);
    swap(&a, &b);
    printf("After swapping:  a = %d and b = %d\n", a, b);

    return 0;
}

Output

Enter two numbers: 10 20

Before swapping: a = 10 and b = 20
After swapping:  a = 20 and b = 10