PHP count 统计不到！josn[$key] 的问题

Question

 for($i=0;$i<count($title_json);$i++){
             $key='h'.$i;
             $key_key='hs'.$i;
        for($j=0;$j<count($title_json[$key_key]);$j++){
            $title_json=   $database ->insert("my_hall_solution", [
                "title_id" => $j.'001',
                "catid" => "0",
                "title_h" => $title_json[$key],
                "title_hs" => $title_json[$key_key][$j]
            ]);
        }
    }

count($title_json['key']);

可以

count($title_json[$key_key]);

报错！ 取不到！！！

Answer 1

$key_key = “key”;
count($title_json[$key_key]);
这样