NULL
Domains:
PHP
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;
?>
See also the functions is_null() and unset().
Casting to NULL
Warning
This feature has been DEPRECATED as of PHP 7.2.0. 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.