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# empty

(PHP 3, PHP 4, PHP 5 )

empty -- Determine whether a variable is empty

## Description

bool empty ( mixed var)

empty() returns `FALSE` if `var` has a non-empty and non-zero value. In otherwords, `""`, `0`, `"0"`, `NULL`, `FALSE`, `array()`, `var $var;`, and objects with empty properties, are all considered empty. `TRUE` is returned if `var` is empty.

empty() is the opposite of `(boolean) `var``, except that no warning is generated when the variable is not set. See converting to boolean for more information.

Example 1. A simple empty() / isset() comparison.
`<?php $var = 0; // Evaluates to true because $var is empty if (empty($var)) { echo '$var is either 0, empty, or not set at all'; } // Evaluates as true because $var is set if (isset($var)) { echo '$var is set even though it is empty'; } ?>`

> Note: Because this is a language construct and not a function, it cannot be called using variable functions

> Note: empty() only checks variables as anything else will result in a parse error. In otherwords, the following will not work: empty(addslashes($name)).

See also isset(), unset(), array_key_exists(), count(), strlen(), and the type comparison tables.

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