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<?php
  $test = null;
?>

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

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

But with echo we won't see anything:

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

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

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