is_null()
is_null() — Finds whether a variable is null.
Built-in function of PHP 8.5. The manual lists it as available in PHP 4 >= 4.0.4, PHP 5, PHP 7, PHP 8. This page is the reference card: signature, parameters and return value, plus the changelog and the example the manual provides.
Signature
is_null(mixed $value): bool
Parameters
| Parameter | Type | What it takes |
|---|---|---|
| $value | mixed | The variable being evaluated. |
Return value
Returns true if value is null, false otherwise.
Example
A runnable snippet:
error_reporting(E_ALL); $foo = NULL; var_dump(is_null($inexistent), is_null($foo));
See also
is_bool(), is_numeric(), is_float(), is_int(), is_string(), is_object(), is_array()
All PHP 8.5 built-in functions
Reference card built from the PHP manual page is_null() (PHP documentation, CC BY 3.0). The page is generated from the manual, so the wording of the parameter and return value text follows php.net.