## Example

`

     array array_keys ( array $input [, mixed $search_value [, bool $strict = false ]] )

`

## Description

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.

## Return Values

Returns an array of all the keys in input.