/Javascript/React/Conditional Rendering in React js

Conditional Rendering in React js

Ternary react

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

Source: reactjs.org

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>
  );
}

Source: reactjs.org

React style ternary operator

<img 
  src={this.state.photo} 
  alt="" 
  style={ isLoggedIn ? { display:'block'} : {display : 'none'} }  
/>

// or

<img
  src={this.state.photo} 
  alt=""
  style={ { display: isLoggedIn ? 'block' : 'none' } }  
/>

Conditional Rendering in React js

function UserGreeting(props) {
  return <h1>Welcome back!</h1>;
}

function GuestGreeting(props) {
  return <h1>Please sign up.</h1>;
}

function Greeting(props) {
  const isLoggedIn = props.isLoggedIn;
  if (isLoggedIn) {
    return <UserGreeting />;
  }
  return <GuestGreeting />;
}

ReactDOM.render(
  // Try changing to isLoggedIn={true}:
  <Greeting isLoggedIn={false} />,
  document.getElementById('root')
);

Source: reactjs.org

Similar codes

0 vote212 views1 answer
React Fractional rating
Javascript React
0 vote205 views2 answers
Undo npm run eject react
Javascript React
0 vote191 views2 answers
React typical
Javascript React
0 vote222 views1 answer
React notification
Javascript React
2 votes196 views1 answer
React native socket io
Javascript React
0 vote186 views1 answer
Npm: Create react chrome extension
Javascript React
0 vote245 views1 answer
Discord bot remove message reaction
Javascript React
0 vote233 views1 answer
Clear input field react-hook-form
Javascript React
1 vote210 views1 answer
Set Custom User Agent react
Javascript React
2 votes175 views1 answer
If back react
Javascript React