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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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