array_change_key_case

array_change_key_case — Changes all keys in an array
Description
array array_change_key_case ( array $input [, int $case = CASE_LOWER ] )

Returns an array with all keys from input lowercased or uppercased. Numbered indices are left as is.
Parameters

input

The array to work on
case

Either CASE_UPPER or CASE_LOWER (default)

Return Values

Returns an array with its keys lower or uppercased, or FALSE if input is not an array.
Errors/Exceptions

Throws E_WARNING if input is not an array.
Examples

Example #1 array_change_key_case() example
<?php
$input_array = array("FirSt" => 1, "SecOnd" => 4);
print_r(array_change_key_case($input_array, CASE_UPPER));
?>

The above example will output:

Array
(
[FIRST] => 1
[SECOND] => 4
)