- print_r: documentation ( source)
- array_filter: documentation ( source)
- in_array: documentation ( source)
<?php
$array1 = array ("apple","banana","papaya","watermelon","avocado");
$array2 = array ("apple","avocado");
$array1 = array_filter($array1, function($item) use($array2) { return !in_array($item, $array2); });
print '<pre>';
print_r($array1);