const user = {
 firstName: 'Harper',
 lastName: 'Perez'
};
const element = (    //將JSX語句保存在變量中
 <h1>
  Hello, {formatName(user)}!  {/* {}中寫js語句*/}
 </h1>
);

ReactDOM.render(
 element,        //通過JSX變量渲染react節(jié)點
 document.getElementById('root')
);

const element = <div tabIndex="0"></div>;
const element = <img src={user.avatarUrl}></img>;

const ele= <div className="red">Red Color</div>

const ele=<div style="color:red">Red</div>     //會報錯
const ele= <div style={{color:'red'}}>Red</div>

const element = <img src={user.avatarUrl} />;

const element = (
 <div>
  <h1>Hello!</h1>
  <h2>Good to see you here.</h2>
 </div>
);

class Toggole extends React.Component{
 constructor(props){
  super(props);
  this.state={
   flag:true
  };
  this.shiftFlag=this.shiftFlag.bind(this);   //函數(shù)shiftFlag綁定this
 }
 shiftFlag(e){
  e.preventDefault();
  this.setState({
   flag:!this.state.flag
  });
 }
 render(){
  return <a href="#" rel="external nofollow" onClick={this.shiftFlag}>{this.state.flag?'ON':'OFF'}</a>
 }
}

class Name extends React.Component{
 constructor(props){
  super(props);
  this.state={
   name:'default'
  }
 }
 setName(name,e){   //事件e放在最后
  this.setState({
   name:name
  })
 }
 render(){
  return <button onClick={this.setName.bind(this,'tory')}>{this.state.name}</button>
 }
}