{"width":"100%","description":"\u30af\u30e9\u30b9\u3084\u3089\u30aa\u30d6\u30b8\u30a7\u30af\u30c8\u306e\u30e1\u30f3\u30d0\u30fc\u304c\u3059\u3079\u3066 undefined \u304b\u3069\u3046\u304b\u8abf\u3079\u305f\u3044\u3068\u304d\u306f\u4ee5\u4e0b\u306e\u30b3\u30fc\u30c9\u3067\u51fa\u6765\u308b\u3002 const obj = { a: undefined, b: undefined, c: undefined, }; const obj1 = { ...obj }; const obj2 = { ...obj, d: null }; const checkAllMembersAreUndefined = (o: any) => Object.values(o).every(w => w === undefined); console.log(checkAllMembersAreUnde\u2026","height":"190","url":"https://tech.natsuneko.blog/entry/2022/03/25/check-all-members-are-undefined-in-javascript","title":"JavaScript \u3067\u30e1\u30f3\u30d0\u30fc\u304c\u3059\u3079\u3066 undefined \u304b\u3069\u3046\u304b\u3092\u8abf\u3079\u305f\u3044","version":"1.0","provider_url":"https://hatena.blog","html":"<iframe src=\"https://hatenablog-parts.com/embed?url=https%3A%2F%2Ftech.natsuneko.blog%2Fentry%2F2022%2F03%2F25%2Fcheck-all-members-are-undefined-in-javascript\" title=\"JavaScript \u3067\u30e1\u30f3\u30d0\u30fc\u304c\u3059\u3079\u3066 undefined \u304b\u3069\u3046\u304b\u3092\u8abf\u3079\u305f\u3044 - \u306a\u3064\u306d\u3053\u30e1\u30e2\" class=\"embed-card embed-blogcard\" scrolling=\"no\" frameborder=\"0\" style=\"display: block; width: 100%; height: 190px; max-width: 500px; margin: 10px 0px;\"></iframe>","author_url":"https://blog.hatena.ne.jp/yunagi_n/","type":"rich","provider_name":"Hatena Blog","published":"2022-03-24 15:00:00","author_name":"yunagi_n","image_url":null,"blog_url":"https://tech.natsuneko.blog/","blog_title":"\u306a\u3064\u306d\u3053\u30e1\u30e2","categories":["JavaScript","TypeScript"]}