Php/docs/function.is-null

• PHP Manual
• Variable handling Functions
• Finds whether a variable is NULL

is_null

(PHP 4 >= 4.0.4, PHP 5, PHP 7)

is_null — Finds whether a variable is NULL

Description

is_null ( mixed $var ) : bool

Finds whether the given variable is NULL.

Parameters

var

The variable being evaluated.

Return Values

Returns TRUE if var is null, FALSE otherwise.

Examples

Example #1 is_null() example

<?phperror_reporting(E_ALL);$foo = NULL;var_dump(is_null($inexistent), is_null($foo));?>

Notice: Undefined variable: inexistent in ...
bool(true)
bool(true)

See Also

• The NULL type
• isset() - Determine if a variable is declared and is different than NULL
• is_bool() - Finds out whether a variable is a boolean
• is_numeric() - Finds whether a variable is a number or a numeric string
• is_float() - Finds whether the type of a variable is float
• is_int() - Find whether the type of a variable is integer
• is_string() - Find whether the type of a variable is string
• is_object() - Finds whether a variable is an object
• is_array() - Finds whether a variable is an array