Program to Swap Elements Using Call by Reference
#include <stdio.h> void cyclicSwap(int *a, int *b, int *c); int main() { int a, b, c; printf("Enter a, b and c respectively: "); scanf("%d %d %d", &a, &b, &c); printf("Value before swapping:\n"); printf("a = %d \nb = %d \nc = %d\n", a, b, c); cyclicSwap(&a, &b, &c); printf("Value after swapping:\n"); printf("a = %d \nb = %d \nc = %d", a, b, c); return 0; } void cyclicSwap(int *n1, int *n2, int *n3) { int temp; // swapping in cyclic order temp = *n2; *n2 = *n1; *n1 = *n3; *n3 = temp; }
Output
Enter a, b and c respectively: 1 2 3 Value before swapping: a = 1 b = 2 c = 3 Value after swapping: a = 3 b = 1 c = 2
Here, the three numbers entered by the user are stored in variables
a, b and c respectively. The addresses of
these numbers are passed to the
cyclicSwap() function.
cyclicSwap(&a, &b, &c);
In the function definition of
cyclicSwap(), we have assigned
these addresses to pointers.
cyclicSwap(int *n1, int *n2, int *n3) { ... }
When n1, n2 and n3 inside
cyclicSwap() are changed, the values of a,
b and c inside
main() are also changed.
Note: The
cyclicSwap() function is not returning
anything.