--TEST-- Test array_change_key_case() function : usage variations - multidimensional arrays --FILE-- array('one' => 1, 'two' => 2, 'three' => 3), 'French' => array('un' => 1, 'deux' => 2, 'trois' => 3), 'German' => array('eins' => 1, 'zwei' => 2, 'drei' => 3)); echo "\n-- Pass a two-dimensional array as \$input argument --\n"; var_dump(array_change_key_case($input, CASE_UPPER)); echo "\n-- Pass a sub-array as \$input argument --\n"; var_dump(array_change_key_case($input['English'], CASE_UPPER)); echo "Done"; ?> --EXPECT-- *** Testing array_change_key_case() : usage variations *** -- Pass a two-dimensional array as $input argument -- array(3) { ["ENGLISH"]=> array(3) { ["one"]=> int(1) ["two"]=> int(2) ["three"]=> int(3) } ["FRENCH"]=> array(3) { ["un"]=> int(1) ["deux"]=> int(2) ["trois"]=> int(3) } ["GERMAN"]=> array(3) { ["eins"]=> int(1) ["zwei"]=> int(2) ["drei"]=> int(3) } } -- Pass a sub-array as $input argument -- array(3) { ["ONE"]=> int(1) ["TWO"]=> int(2) ["THREE"]=> int(3) } Done