array_change_key_case Changes all keys in an array &reftitle.description; arrayarray_change_key_case arrayinput intcaseCASE_LOWER Returns an array with all keys from input lowercased or uppercased. Numbered indices are left as is. &reftitle.parameters; input The array to work on case Either CASE_UPPER or CASE_LOWER (default) &reftitle.returnvalues; Returns an array with its keys lower or uppercased, or &false; if input is not an array. &reftitle.errors; Throws E_WARNING if input is not an array. &reftitle.examples; 1, "SecOnd" => 4); print_r(array_change_key_case($input_array, CASE_UPPER)); ?> ]]> &example.outputs; 1 [SECOND] => 4 ) ]]> &reftitle.notes; If an array has indices that will be the same once run through this function (e.g. "keY" and "kEY"), the value that is later in the array will override other indices.