mysqli_stmt_bind_param($post, 'ssssssssss', $key[0], $value[0], $key[1], $value[1], $key[2], $value[2], $key2[0], $value2[0], $key2[1], $value2[1]);

public function update($table, $data, $conditions, $comparator) {
        $key = array_keys($data);
        $value = array_values($data);
        $key2 = array_keys($conditions);
        $value2 = array_values($conditions);
        $post = mysqli_prepare($this->mysqli, "UPDATE $table SET ? = ?, ? = ?, ? = ? WHERE ? = ? $comparator ? = ?");
        mysqli_stmt_bind_param($post, 'ssssssssss', $key[0], $value[0], $key[1], $value[1], $key[2], $value[2], $key2[0], $value2[0], $key2[1], $value2[1]);
        mysqli_stmt_execute($post);
    }