array_keys

(PHP 4 )

array_keys -- Return all the keys of an array

Description

array array_keys (array input [, mixed search_value])

Array_keys() returns the keys, numeric and string, from the input array.

If the optional search_value is specified, then only the keys for that value are returned. Otherwise, all the keys from the input are returned.

Esempio 1. Array_keys() example


$array = array (0 => 100, "color" => "red");
array_keys ($array);       // returns array (0, "color")

$array = array ("blue", "red", "green", "blue", "blue");
array_keys ($array, "blue");  //  returns array (0, 3, 4) 
      

See also array_values().