To
understand this example, you should have the knowledge of the following C programming topics:
·
C Arrays
·
Pass arrays to a function in C
·
C Arrays
·
Relationship Between Arrays and Pointers
·
C Pass Addresses and Pointers
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;
}
OutputEnter 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) {
...
}
Labels : #c ,#code ,#examples ,When n1, n2 and n3 inside
cyclicSwap()
are changed, the values of a, b and c insidemain()
are also changed.Note: The
cyclicSwap()
function is not returning anything.