key vs id react code example

Example 1: react component key prop

function ListItem(props) {
  // Correct! There is no need to specify the key here:  return <li>{props.value}</li>;}

function NumberList(props) {
  const numbers = props.numbers;
  const listItems = numbers.map((number) =>
    // Correct! Key should be specified inside the array.    <ListItem key={number.toString()} value={number} />  );
  return (
    <ul>
      {listItems}
    </ul>
  );
}

const numbers = [1, 2, 3, 4, 5];
ReactDOM.render(
  <NumberList numbers={numbers} />,
  document.getElementById('root')
);

Example 2: react create list of array in react

const App = props => {  const quoteArray = props.quotes.map((quote) => {    return (      <Quote text={quote.text} author={quote.author} />    );  });  return (    <div>      <h2>Famous Quotes</h2>      {quoteArray}    </div>  );};App.propTypes = {  quotes: React.PropTypes.array}