1 useState简单实现 1.1 示例 点击按钮,结果+1 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 import React from "react"; import ReactDOM from "react-dom"; const rootElement = document.getElementById("root"); function App() { const [n, setN] = React.useState(0); return ( <div className="App"> <p>{n}</p> <p> <button onClick={()