PHP將字符轉數組

explode(',',$arr_string)

//將字符串轉數組
$arr_string = '1,2,3';
$arr = explode(',',$arr_string);
dump($arr);

//打印輸出以下
array(3) {
  [0] => string(1) "1"
  [1] => string(1) "2"
  [2] => string(1) "3"
}