Three variables entered by the user are stored in variables a, b and c respectively.

Then, these variables are passed to the function cyclicSwap(). Instead of passing the actual variables, addresses of these variables are passed.

When these variables are swapped in cyclic order in the cyclicSwap() function, variables a, b and c in the main function are also automatically swapped.

Example: Program to Swap Elements Using Call by Reference

#include<iostream>
using namespace std;

void cyclicSwap(int *a, int *b, int *c);

int main(){
    int a, b, c;

    cout << "Enter value of a, b and c respectively: ";
    cin >> a >> b >> c;

    cout << "Value before swapping: " << endl;
    cout << "a, b and c respectively are: " << a << ", " << b << ", " << c << endl;

    cyclicSwap(&a, &b, &c);

    cout << "Value after swapping numbers in cycle: " << endl;
    cout << "a, b and c respectively are: " << a << ", " << b << ", " << c << endl;

    return 0;
}

void cyclicSwap(int *a, int *b, int *c){
    int temp;
    temp = *b;
    *b = *a;
    *a = *c;
    *c = temp;
}

Output

Enter value of a, b and c respectively: 1
2
3
Value before swapping: 
a=1
b=2
c=3
Value after swapping numbers in cycle:
a=3
b=1
c=2

Notice that we haven’t returned any values from the cyclicSwap() function.