react list rendering

1const numbers = [1, 2, 3, 4, 5];
2const listItems = numbers.map((number) =>  <li>{number}</li>);

1function Blog(props) {
2  const sidebar = (    <ul>
3      {props.posts.map((post) =>
4        <li key={post.id}>          {post.title}
5        </li>
6      )}
7    </ul>
8  );
9  const content = props.posts.map((post) =>    <div key={post.id}>      <h3>{post.title}</h3>
10      <p>{post.content}</p>
11    </div>
12  );
13  return (
14    <div>
15      {sidebar}      <hr />
16      {content}    </div>
17  );
18}
19
20const posts = [
21  {id: 1, title: 'Hello World', content: 'Welcome to learning React!'},
22  {id: 2, title: 'Installation', content: 'You can install React from npm.'}
23];
24ReactDOM.render(
25  <Blog posts={posts} />,
26  document.getElementById('root')
27);