React Hooksのメモ - Qiita

import React, {useState} from "react"; import ReactDOM from "react-dom"; //function App()でも可 var App = function() { //現在の値と値を更新する関数を取得 //useState(n)のnがcntの初期値になる var [cnt, setCount] = useState(0); var addCount = function() { setCount(cnt + 1); } var minusCount = function() { setCount(cnt - 1); } return ( <> <div> <p>Hello React!!</p> <input type="button" value="+1" onClick={() => addCount()} /> <i