为什么我这个评论区渲染不出来？

import React from 'react';
import ReactDOM from 'react-dom';


class App extends React.Component {
  //初始化状态
  state = {
    comments:[
      {id:1,name:"jack",content:"沙发！！！"},
      {id:2,name:"rose",content:"板凳~"},
      {id:3,name:"tom",content:"楼主好人"}
    ]
  }
  render(){
    return (
      <div className="app">
        <div>
          <input className="user" type="text" placeholder="请输入评论人" />
          <br />
          <textarea
            className="content"
            cols="30"
            rows="10"
            placeholder="请输入评论内容"
          />
          <br />
          <button>发送评论</button>
        </div>

        <div className="no-comment">暂无评论，快去评论吧~</div>
        <ul>
        {this.state.comments.forEach(item => {
            <li key={item.id}>
              <h3>评论人：{item.name}</h3>
              <p>评论内容:{item.content}</p>
            </li>
            })}
        </ul>
      </div>
    )
  }
}

ReactDOM.render(<App/>,document.getElementById('root'))

this.state.comments.forEach -> this.state.comments.map，forEach只是遍历而已，并没有任何返回值

forEach()没有返回值

{this.state.comments.map(item => {
            <li key={item.id}>
              <h3>评论人：{item.name}</h3>
              <p>评论内容:{item.content}</p>
            </li>
            })}