react怎么循环列表

<script type="text/babel">
        let arr=["吃饭","睡觉","喝水"]
        let MyDom =arr.map((item,index)=>{
            return <p>{item}</p>
        })
        ReactDOM.render(MyDom,document.getElementById("demoReact"))
    </script>

 <script type="text/babel">
        let arr=["吃饭","睡觉","喝水"]
        let MyDom =arr.map((item,index)=>{
        //key值必须是独一无二的
            return <p key={index}>{item}</p>
        })
        ReactDOM.render(MyDom,document.getElementById("demoReact"))
    </script>

//直接回车换行
return 
<p key={index}>{item}</p>

//用括号包裹住换行元素
 let MyDom =arr.map((item,index)=>{
            return (
                <p key={index}>{item}</p>)
        })

 function fun(){
            let newarr=[];
            for(let index in arr){
               newarr.push(<p key={index}>{arr[index]}</p>)
            }
            return newarr;
        }
        
        ReactDOM.render(fun(),document.getElementById("demoReact"))

 function fun(){
            let newarr=[];
            for(var i=0;i<arr.length;i++){
               newarr.push(<p key={i}>{arr[i]}</p>)
            }
            return newarr;
        }

 function fun(){
            arr.forEach(a=>{
             console.log(a);
            })
        }