C program to swap two numbers using call by reference

Write a C program to swap two numbers using call by reference.

  #include <stdio.h>

  /* swap two numbers */
  void swap(int *a, int *b) {
        int temp;
        temp = *a;
        *a = *b;
        *b = temp;
  }

  int main() {
        int a, b;

        /* get two numbers from the user */
        printf("Enter the value for a and b:");
        scanf("%d%d", &a, &b);
        printf("Before Swapping:\n");
        printf("a: %d\tb: %d\n", a, b);

        /* call by reference */
        swap(&a, &b);

        /* printing the results after swapping */
        printf("After Swapping:\n");
        printf("a: %d\tb: %d\n", a, b);
        return 0;
  }

  Output:

  jp@jp-VirtualBox:~/$ ./a.out
  Enter the value for a and b: 100   200
  Before Swapping:
  a: 100 b: 200
  After Swapping:
  a: 200 b: 100