JAVASCRIPT

react array.map with return

const robots = ['Bruce', 'Clark', 'Diana']

robots.map((robot, index) => {
                    return (
                        <h1 key={index}>{robot} </h1>
                    )
})

new Map() collection in react state

function MapComponent(){
  const [myMap, setMyMap] = useState(new Map());
  const updateMap = (k,v) => {
    setMyMap(new Map(myMap.set(k,v)));
  }
  return(
    <ul>
      {[...myMap.keys()].map(k => (
        <li key={k}>myMap.get(k)</li>
      ))}
    </ul>
  );
}

Use of map in react

const todoItems = [
  {
    id: 1,
    text:"todo 1"
  },
  {
    id: 2,
    text:"todo 3"
  },
  {
    id: 3,
    text:"todo 3"
  }
];
const todoItems = todos.map((todo) =>
  <li key={todo.id}>
    {todo.text}
  </li>
);

how to map array in react

export const Articles = props => {
  const [articles, setArticle] = React.useState(props.data || [])
  React.useEffect(() => {
    if (Array.isArray(articles) && articles.length < 1) {
      setArticle([
        {
          title: 'how to map array in react',
          content: `read this code!`,
        },
      ])
    }
  }, [articles])
  return (
    <div>
      {Array.isArray(articles) &&
        articles.map((item, key) => (
          <article key={key}>
            <h2>{item.title}</h2>
            <p>{item.content}</p>
          </article>
        ))}
    </div>
  )
}