➤ Two numbers can be swapped or interchanged. It means first number will become second and second number will become first. For instance: • Swapping Using Third Variable

$x = 5;  
$y = 10;  
// Swapping Logic  
$temp = $x;  
$x = $y;  
$y = $temp;  
echo "After swapping: ";  
echo "\n x = $x \n y = $y";  
// outputs :  x = 10   y = 5

• Swap two numbers without using a third variable - Using arithmetic operation + and ?

$x = 5;  
$y = 10;  
$x = $x + $y;  // 15
$y = $x - $y;  // 5
$x = $x - $y;  // 10
echo "After swapping: ";  
echo "\n x = $x \n y = $y";  
// outputs :  x = 10   y = 5

- Using arithmetic operation * and /

$x = 5;  
$y = 10;  
$x = $x*$y;  // 50
$y = $x/$y;  // 5
$x = $x/$y;  // 10
echo "After swapping: ";  
echo "\n x = $x \n y = $y";  
// outputs :  x = 10   y = 5