<?php

function a() {
  $array1 = array(
    "a" => "green",
    "b" => "brown",
    "c" => "blue",
    "red"
  );
  $array2 = array(
    "a" => "green",
    "yellow",
    "red"
  );

  $result = array_diff_assoc($array1, $array2);
  var_dump($result);
}

function b() {
  $array1 = array(0, 1, 2);
  $array2 = array("00", "01", "2");
  $result = array_diff_assoc($array1, $array2);
  var_dump($result);
}

a();
b();