Swap Two Variables Using XOR

In C++, variables are containers that store data. Sometimes, we may need to swap the values of two variables. The traditional method involves using a third variable as a temporary storage to facilitate the swap. In this article, we will learn how to swap two variables using the XOR technique.

Example:

Input: a = 5; b = 10;
Output: a = 10; b = 5;

Swapping Two Variables Using XOR in C++

The XOR operator returns true if the number of true inputs is odd. To swap two variables using XOR in C++, wc can do it byBy performing the XOR operation on the two variables three times, we can swap their values without using a third variable. Here’s how it works:

C++ Program to Swap Two Variables Using XOR

C++ Program to Swap Two Variables Using XOR

C++

// C++ Program to illustrate how to swap two variables
// without using a third variable in C++.
#include <iostream>
using namespace std;

// main function
int main()
{

    // variable definition
    int a = 2, b = 3;

    // initial value
    cout << "Before swapping the variables a= " << a
         << " b= " << b;
    cout << endl;

    // swapping logic
    a = a + b;
    b = a - b;
    a = a - b;

    // final value
    cout << "After swapping the variables a= " << a
         << " b= " << b << endl;
    return 0;
}

Output

Before swapping the variables a= 2 b= 3
After swapping the variables a= 3 b= 2

Time Complexity: O(1)
Space Complexity: O(1)