--TEST-- Test array_keys() function (variation - 3) --FILE-- TRUE, FALSE => FALSE, 1 => 1, 0 => 0, -1 => -1, "1" => "1", "0" => "0", "-1" => "-1", NULL, array(), "php" => "php", "" => "" ); $values = array(TRUE, FALSE, 1, 0, -1, "1", "0", "-1", NULL, array(), "php", ""); foreach ($values as $value){ var_dump($value); var_dump(array_keys($types_arr, $value)); } echo "Done\n"; ?> --EXPECT-- *** Testing array_keys() on all the types other than arrays *** bool(true) array(3) { [0]=> int(1) [1]=> int(-1) [2]=> string(3) "php" } bool(false) array(4) { [0]=> int(0) [1]=> int(2) [2]=> int(3) [3]=> string(0) "" } int(1) array(1) { [0]=> int(1) } int(0) array(2) { [0]=> int(0) [1]=> int(2) } int(-1) array(1) { [0]=> int(-1) } string(1) "1" array(1) { [0]=> int(1) } string(1) "0" array(1) { [0]=> int(0) } string(2) "-1" array(1) { [0]=> int(-1) } NULL array(3) { [0]=> int(2) [1]=> int(3) [2]=> string(0) "" } array(0) { } array(2) { [0]=> int(2) [1]=> int(3) } string(3) "php" array(1) { [0]=> string(3) "php" } string(0) "" array(2) { [0]=> int(2) [1]=> string(0) "" } Done