Basics - Lists & keys example 5. Using map( ) in JSX.

App.js

import React, { Component } from "react";

class App extends Component {
  render() {
    const numbers = [1, 2, 3, 4, 5];
    return (
      <ul>
        {numbers.map(number => (
          <li key={number.toString()}>{number}</li>
        ))}
      </ul>
    );
  }
}

export default App;