$invite1 = '18,19,20,21,22';
$invite2 = '18,19';
$a = explode(",",$invite1);
$b = explode(",",$invite2);
foreach ($a as $key=>$v1) {
foreach($b as $key2=>$v2){
if($v1==$v2){
unset($a[$key]);//删除$a数组同值元素
unset($b[$key2]);//删除$b数组同值元素
}
}
}
var_dump($a);
var_dump($b);