Objectを利用する際の参考

基礎

https://qiita.com/yoshi389111/items/245df2d642e49d2acf3a

https://qiita.com/masarufuruya/items/d29a567d0ca4bbfb00cb

ループ

https://qiita.com/endam/items/808a084859e3a101ab8f