The Null Value in PHP

In PHP, there is another special value null, which means "nothing". For example, we can assign this value to a variable to signify that there is nothing there.

Let's look at an example:

<?php
	$test = null;
?>

Let's output the value of our variable using var_dump:

<?php
	$test = null;
	var_dump($test); // will output null
?>

But with echo we won't see anything:

<?php
	$test = null;
	echo $test;      // will output emptiness
?>

By default, variables that have not been declared in the code have the value null:

<?php
	var_dump($test); // will output null
?>

Assign the value null to a variable. Output this variable to the screen.

Output the value of any undeclared variable to the screen.