PHP数组分割成新数组 阿星小栈

   public static function arrOper ( $arr, $num ) {

        $count = count ( $arr );
        $return_arr = [];
        for ( $i = 0; $i < $count / $num; $i ++ ) {
            $return_arr[$i] = array_slice ( $arr, $num * $i, $num);
        }
        return $return_arr;
    }