kikiki-kiki https://blog.hatena.ne.jp/kikiki-kiki/ かもメモ https://chaika.hatenablog.com/ TypeScript React JavaScript React の useState で返される state の型を指定したい useState<型>(initial value) で state に型を強制できる type IdolType = 'cute' | 'cool' | 'pop' | 'sexy'; const [type, setType] = useState<IdolType>('cute'); setType('foo'); // => Argument of type '"foo"' is not assignable to parameter of type 'SetStateAction<IdolType>' set… 190 <iframe src="https://hatenablog-parts.com/embed?url=https%3A%2F%2Fchaika.hatenablog.com%2Fentry%2F2020%2F08%2F16%2F083000" title="React TypeScript useState に型を設定したい - かもメモ" class="embed-card embed-blogcard" scrolling="no" frameborder="0" style="display: block; width: 100%; height: 190px; max-width: 500px; margin: 10px 0px;"></iframe> https://m.media-amazon.com/images/I/41TW3EHwQPL._SL160_.jpg Hatena Blog https://hatena.blog 2020-08-16 08:30:00 rich https://chaika.hatenablog.com/entry/2020/08/16/083000 1.0 100%