(PHP 4 >= 4.2.0)
array_change_key_case -- Returns an array with all string keys lowercased or uppercasedarray_change_key_case() changes the keys in the input array to be all lowercase or uppercase. The change depends on the last optional case parameter. You can pass two constants there, CASE_UPPER and CASE_LOWER. The default is CASE_LOWER. The function will leave number indices as is.