C++ Program to swap two numbers without using a third variable with a call by reference

---

In this program, You will learn how to swap two numbers without using a third variable with a call by reference in C++.

---

Call by Reference

void swap(int *x, int *y){ 
   //statement
}

Example: How to swap two numbers without using a third variable with a call by reference in C++.

#include<iostream>
using namespace std;

void swap(int *x, int *y) {
    *(x) = *(x) + *(y);
    *(y) = *(x) - *(y);
    *(x) = *(x) - *(y);
}

int main() {

    int a, b, s;

    cout << "Enter two numbers:";
    cin >> a >> b;

    swap(&a, &b);

    cout << "After swap a is : " << a;
    cout << "\nAfter swap b is : " << b;

    return 0;
}

Output:

Enter two numbers:10 20
After swap a is : 20
After swap b is : 10