NULL
The special null
value represents a variable with no value. null
is the
only possible value of type null.
A variable is considered to be null if:
-
it has been assigned the constant
null
. -
it has not been set to any value yet.
-
it has been unset().
Syntax
There is only one value of type null, and that is the
case-insensitive constant null
.
<?php
$var = NULL;
?>
Casting to null
This feature has been DEPRECATED as of PHP 7.2.0, and REMOVED as of PHP 8.0.0. Relying on this feature is highly discouraged.
Casting a variable to null using (unset) $var
will not remove the variable or unset its value.
It will only return a null
value.