PHP - Function array_keys()

Syntax

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

Definition and Usage

It returns the keys, numeric and string, from the input array.

Parameters

Sr.No	Parameter & Description
1	input(Required) It specifies an array.
2	search_value(Required) You can specify a value, then only the keys with this value are returned.
3	strict Optional. Used with the value parameter.

Parameter & Description

input(Required)

It specifies an array.

search_value(Required)

You can specify a value, then only the keys with this value are returned.

Optional. Used with the value parameter.

Return Values

It returns the keys, numeric and string, from the input array

Example

Try out following example −

Live Demo

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

This will produce the following result −

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

php_function_reference.htm