Pass by Value and Reference Example in PHP

Published: Feb 19, 2021 - Updated: Mar 16, 2022

Hi artisans, in this short article, I’m going to write about the pass by value and pass by reference. I’ll show examples in PHP & will explain simply. Let’s see:

Table of Contents

  1. Pass by Value
  2. Pass by Reference

Pass by Value

“Pass by value” means that we pass the actual value of the variable into a function. Let’s look at the following example:

function function_name($string) {
    $string = "I'm from function";
    print($string);
}

$string = "I'm from outside of function";
function_name($string);
echo "
"; print($string);

The output:

I'm from function
I'm from outside of function

Pass by Reference

“Pass by Reference” means that we pass the variable itself into the function with the value. We need to add & (ampersand) symbol before the variable name. The value of the outside variable will be changed too. Because both variables are defined by the same reference. Have a look at an example:

function function_name(&$string) {
    $string = "I'm from function";
    print($string);
}

$string = "I'm from outside of function";
function_name($string);
echo "
"; print($string);

The output:

I'm from function
I'm from function
That’s all. Thanks for reading. ?