<?php
function foo1 ($a, $b){
$c = [];
foreach ($a as $val){
if (!in_array($val, $b)){
$c[] = $val;
}
}
return $c;
}
$a = [3, 5, 7];
$b = [4, 5, 9];
$c = foo1($a, $b);
var_dump($c);
function foo ($a, $b) {
// $arr1 = array_unique($a);
// $arr2 = array_unique($b);
$arr1 = $a;
$arr2 = $b;
// if (count($arr1) < count($arr2)) {
// list($arr1, $arr2) = [$arr2, $arr1];
// }
return array_diff($arr1,$arr2);
}
$a = [3, 5, 7,5,0, 0, 2];
$b = [4, 5, 9, ];
var_dump(foo($a, $b));
var_dump(foo($a, $b));