PHP Function array_keys()

Syntax

array_keys ( $input [, $search_value [, $strict]] );

Definition and Usage

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.

Paramters

Parameter	Description
input	Required.Specifies an array.
search_value	Required. You can specify a value, then only the keys with this value are returned.
strict	Optional. Used with the value parameter. Possible values: * true - Returns the keys with the specified value, depending on type: the number 5 is not the same as the string "5". * false - Default value. Not depending on type, the number 5 is the same as the string "5".

Return Values

Returns the keys, numeric and string, from the input array

Example

Try out following example:

<?php $a=array("a"=>"Horse","b"=>"Cat","c"=>"Dog"); print_r(array_keys($a)); $a=array("a"=>"Horse","b"=>"Cat","c"=>"Dog"); print_r(array_keys($a,"Dog")); $a=array(10,20,30,"10"); print_r(array_keys($a,"10",false)); ?>

This will produce following result:

Array ( [0] => a [1] => b [2] => c ) Array ( [0] => c) Array ( [0] => 0 [1] => 3 )