Swap two variables in one line in C/C++, Python, PHP and Java

In this tutorial, we are going to learn how to swap two variables in different languages. Swapping means interchanging the values of two variables. Let's see an example.

Input

a = 3 b = 5

Output

a = 5 b = 3

Let's see how to achieve this in different programming languages.

Python

We can swap variables with one line of code in Python using tuple unpacking −

Example

# initializing the variables
a, b = 3, 5
# printing before swapping
print("Before swapping:-", a, b)
# swapping
a, b = b, a
# printing after swapping
print("After swapping:-", a, b)

Output

Before swapping:- 3 5
After swapping:- 5 3

XOR Method for C/C++, PHP, and Java

In languages like C/C++, PHP, and Java, we can use the XOR operator to swap variables in one line. The XOR method works through these steps −

• Perform XOR operation on two variables and assign the result to the first variable
• Perform XOR operation and assign the result to the second variable
• Perform XOR operation and assign the result to the first variable again
• The variables will be swapped

C/C++

Example

#include <stdio.h>
int main() {
    int a = 3, b = 5;
    printf("Before Swapping:- %d %d\n", a, b);
    (a ^= b), (b ^= a), (a ^= b);
    printf("After Swapping:- %d %d\n", a, b);
    return 0;
}

Output

Before Swapping:- 3 5
After Swapping:- 5 3

Java

Example

class Swap {
    public static void main (String[] args) {
        int a = 3, b = 5;
        System.out.println("Before Swapping:- " + a + " " + b);
        a = a ^ b ^ (b = a);
        System.out.println("After Swapping:- " + a + " " + b);
    }
}

Output

Before Swapping:- 3 5
After Swapping:- 5 3

PHP

Example

<?php
    $a = 5;
    $b = 10;
    echo "Before Swapping:- $a $b\n";
    ($a ^= $b), ($b ^= $a), ($a ^= $b);
    echo "After Swapping:- $a $b\n";
?>

Output

Before Swapping:- 5 10
After Swapping:- 10 5

Conclusion

Python offers the most elegant solution with tuple unpacking, while other languages can achieve one−line swapping using the XOR operator. The XOR method works efficiently for integer values without requiring temporary variables.