Swap Two Variables in One Line

We have discussed different approaches to swap two integers without the temporary variable. How to swap into a single line without using the library function?
1) Python: In Python, there is a simple and syntactically neat construct to swap variables, we just need to write “x, y = y, x”.
2) C/C++: Below is one generally provided classical solution: 

// Swap using bitwise XOR (Wrong Solution in C/C++)
x ^= y ^= x ^= y; 

The above solution is wrong in C/C++ as it causes undefined behavior (the compiler is free to behave in any way). The reason is, modifying a variable more than once in an expression causes undefined behavior if there is no sequence point between the modifications. 
However, we can use a comma to introduce sequence points. So the modified solution is 

// Swap using bitwise XOR (Correct Solution in C/C++)
// sequence point introduced using comma.
(x ^= y), (y ^= x), (x ^= y);

3) Java: In Java, rules for subexpression evaluations are clearly defined. The left-hand operand is always evaluated before the right-hand operand. In Java, the expression “x ^= y ^= x ^= y;” doesn’t produce the correct result according to Java rules. It makes x = 0. However, we can use “x = x ^ y ^ (y = x);” Note the expressions are evaluated from left to right. If x = 5 and y = 10 initially, the expression is equivalent to “x = 5 ^ 10 ^ (y = 5);”. Note that we can’t use this in C/C++ as in C/C++, it is not defined whether the left operand or right operand is executed by any operator (See this for more details).

4) JavaScript: Using destructing assignment, we can simply achieve swapping using this one line. 

[x,y]=[y,x]

C

// C program to swap two variables in single line
#include <stdio.h>
int main()
{
    int x = 5, y = 10;
    (x ^= y), (y ^= x), (x ^= y);
    printf("After Swapping values of x and y are %d %d", x,
           y);
    return 0;
}

C++

// C++ code to swap using XOR
#include <bits/stdc++.h>

using namespace std;

int main()
{
    int x = 5, y = 10;
    // Code to swap 'x'  and 'y'
    // to swap two numbers in one
    // line
     x = x ^ y, y = x ^ y, x = x ^ y;
    // printing the swapped variables
    cout << "After Swapping: x = "
         << x << ", y= " << y;
    return 0;
}

Java

// Java program to swap two variables in a single line
class GFG {
    public static void main(String[] args)
    {
        int x = 5, y = 10;
        x = x ^ y ^ (y = x);
        System.out.println(
            "After Swapping values"
            +" of x and y are " + x
            + " " + y);
    }
}

Python3

# Python program to swap two variables in a single line
x = 5
y = 10
x, y = y, x
print("After Swapping values of x and y are", x, y)

C#

// C# program to swap two
// variables in single line
using System;

class GFG {
    static public void Main()
    {
        int x = 5, y = 10;
        x = x ^ y ^ (y = x);
        Console.WriteLine("After Swapping values "
                          + "of x and y are " + x + " "
                          + y);
    }
}

// This code is contributed by aj_36

PHP

<?php
// PHP program to swap two
// variables in single line

    // Driver Code
    $x = 5;
    $y = 10;
    ($x ^= $y);
    ($y ^= $x);
    ($x ^= $y);
    echo "After Swapping values of x and y are "
                                  ,$x," ", $y;

// This code is contributed by Vishal Tripathi
?>

Javascript

<script>
// javascript program to swap two variables in single line

    let x = 5, y = 10;
    (x ^= y), (y ^= x), (x ^= y);
    document.write("After Swapping values of x and y are ", x + " ",
           y);

// This code is contributed by Surbhi Tyagi
</script>

Output

After Swapping values of x and y are 10 5

Alternate Solutions:

1. Using swap(): C++ library function
2. b = (a + b) – (a = b);
3. a += b – (b = a);
4. a = a * b / (b = a)
5. a = a ^ b ^ (b = a)

Time complexity : O(1) 
Auxiliary Space : O(1)