React17 测试

            
            html {
  height: 100%;
}
body {
  height: 100%;
  background: #212121;
  color: #fff;
  display: flex;
  align-items: center;
  justify-content: center;
}
        

            
            


var root = document.createElement("div");
root.id = "root"

const App = React.forwardRef(() => {
  
  const [browsers, setData] = React.useState(
    ["Firefox", "Chrome", "Opera", "Safari", "Internet Explorer"]
  );
  React.useEffect(() => {
    
    console.log("useEffect"),
    setTimeout(() => {
      console.log("useEffect2")
      setData(["dadfds","12313"]);
    }, 1000)
  }, [])

  function handleClick() {
    // alert('你点击了我11！');
    
      setData(["ccccc","dddddd"]);
  }
  
  return <div>
    {browsers.map((browser) => <div key={browser}>{browser}</div>)}
    <button onClick={handleClick}>
      点我
    </button>
  </div>
})


ReactDOM.render(<App />, root);
document.body.appendChild(root);