Php/docs/language.types.null
From Get docs
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; ?>
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.