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array_key_exists

(PHP 4 >= 4.1.0, PHP 5)

array_key_exists -- Checks if the given key or index exists in the array

Description

bool array_key_exists ( mixed key, array search)

array_key_exists returns TRUE if the given key is set in the array. key can be any value possible for an array index.

Example 1. array_key_exists() example

<?php

$search_array = array("first" => 1, "second" => 4);

if (array_key_exists("first", $search_array)) {

   echo "The 'first' element is in the array";

}

?>

Note: The name of this function is key_exists() in PHP 4.0.6.

See also isset(), array_keys() and in_array().