condition in element level reactjs code example

Example 1: conditional jsx property

render() {
  return (
    <a className="navbar-brand" {... url ? {href: url} : {}}>Logo</a>
  )
}

Example 2: react native conditional rendering

function Mailbox(props) {
  const unreadMessages = props.unreadMessages;
  return (
    <div>
      <h1>Hello!</h1>
      {unreadMessages.length > 0 &&
        <h2>
          You have {unreadMessages.length} unread messages.
        </h2>
      }
    </div>
  );
}