return some jsx and also some methods from react component code example

Example 1: ternary react

render() {
  const isLoggedIn = this.state.isLoggedIn;
  return (
    <div>
      The user is <b>{isLoggedIn ? 'currently' : 'not'}</b> logged in.    
	</div>
  );
}

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>
  );
}

Example 3: javascript in jsx

const name = 'Josh Perez';
const element = <h1>Hello, {name}</h1>;
//notice the use of {...} to jump from jsx to javascript.
ReactDOM.render(
  element,
  document.getElementById('root')
);