PHP Call By Value
In this method, values of a variable is passed to a function. On passing a variable value to a function creates another address of the same passed variable. So, when passed parameter process withing function, it doesn’t affect contents of the actual parameter.
Let’s understand with an example –
<?php function increment($value){ $value++; return $value; } $x = 10; $y = increment($x); echo $x; //Output: 10 echo $y; //Output: 11 ?>
Let’s take another example of swapping two numbers-
<?php function swap($x,$y) { $c=$x; $x=$y; $y=$c; } $x1=5; $x2=10; echo "Before calling the function swap:"."<br>"; echo "The two values are: ".$x1." ".$x2."<br>"; swap($x,$y); echo "After calling the function swap:"."<br>"; echo "The two values are: ".$x1." ".$x2."<br>"; ?> //result Before calling the function swap: The two values are: 5 10 After calling the function swap: The two values are: 5 10