How to swap two numbers without using a temporary variable in PHP ?

We have two variables (parameters) “x” & “y”, here we do swap of two variables without using a third variable (parameters).

1) Swap numbers using Arithmetic Operators –
In below example we use addition and subtraction operation to do swap of 2 numbers

<?php
function swap_me()
{
    $x = 25;
    $y = 14;

    echo "Before Swapping: x = ".$x.", y = ".$y;

    // Code to swap "$x" and "$y"
    $x = $x + $y;  // $x now becomes 39
    $y = $x - $y;  // $y becomes 25
    $x = $x - $y;  // $x becomes 14

    echo "<BR>After Swapping: x = ".$x.", y = ".$y;
}

// call the function
swap_me();
?>

Output:
Before Swapping: x = 25, y = 14
After Swapping: x = 14, y = 25

<?php

function swap_me()

{

$x = 25;

$y = 14;

echo "Before Swapping: x = ".$x.", y = ".$y;

// Code to swap "$x" and "$y"

$x = $x + $y; // $x now becomes 39

$y = $x - $y; // $y becomes 25

$x = $x - $y; // $x becomes 14

echo "<BR>After Swapping: x = ".$x.", y = ".$y;

}

// call the function

swap_me();

Output:

Before Swapping: x = 25, y = 14

After Swapping: x = 14, y = 25

In below example we use multiplication and division operation to do swap of 2 numbers

<?php
function swap_me()
{
    $x = 25;
    $y = 14;

    echo "Before Swapping: x = ".$x.", y = ".$y;
 
    // Code to swap "$x" and "$y"
    $x = $x * $y;  // x now becomes 350
    $y = $x / $y;  // y becomes 25
    $x = $x / $y;  // x becomes 14
 
    echo "<BR>After Swapping: x = ".$x.", y = ".$y;
}

// call the function
swap_me();
?>

Output:

Before Swapping: x = 25, y = 14
After Swapping: x = 14, y = 25

<?php

function swap_me()

{

$x = 25;

$y = 14;

echo "Before Swapping: x = ".$x.", y = ".$y;

// Code to swap "$x" and "$y"

$x = $x * $y; // x now becomes 350

$y = $x / $y; // y becomes 25

$x = $x / $y; // x becomes 14

echo "<BR>After Swapping: x = ".$x.", y = ".$y;

}

// call the function

swap_me();

Output:

Before Swapping: x = 25, y = 14

After Swapping: x = 14, y = 25

2) Swap numbers using Bitwise XOR Operators –

<?php
function swap_me()
{
    $x = 25;
    $y = 14;

    echo "Before Swapping: x = ".$x.", y = ".$y;
 
    // Code to swap 'x' (11001) and 'y' (1110)
    $x = $x ^ $y;  // x now becomes 15 (100111)
    $y = $x ^ $y;  // y becomes 10 (11001)
    $x = $x ^ $y;  // x becomes 5 (1110)
 
    echo "<BR>After Swapping: x = ".$x.", y = ".$y;
}

// call the function
swap_me();
?>

Output:

Before Swapping: x = 25, y = 14
After Swapping: x = 14, y = 25

<?php

function swap_me()

{

$x = 25;

$y = 14;

echo "Before Swapping: x = ".$x.", y = ".$y;

// Code to swap 'x' (11001) and 'y' (1110)

$x = $x ^ $y; // x now becomes 15 (100111)

$y = $x ^ $y; // y becomes 10 (11001)

$x = $x ^ $y; // x becomes 5 (1110)

echo "<BR>After Swapping: x = ".$x.", y = ".$y;

}

// call the function

swap_me();

Output:

Before Swapping: x = 25, y = 14

After Swapping: x = 14, y = 25

Note:
In multiplication, we can not able to use 0 (zero), because of it make multiplication result as zero.

Your comments are appreciated!

Till than Happy Coding 🙂

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How to swap two numbers without using a temporary variable in PHP ?

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