conditional statement in react js code example

Example 1: ternary react

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

Example 2: react native conditional rendering

function Mailbox(props) {
  const unreadMessages = props.unreadMessages;
  return (
    

Hello!

{unreadMessages.length > 0 &&

You have {unreadMessages.length} unread messages.

}
); }

Example 3: conditional rendering react

function Mailbox(props) {
  const unreadMessages = props.unreadMessages;
  return (
    

Hello!

{unreadMessages.length > 0 &&

You have {unreadMessages.length} unread messages.

}
); } const messages = ['React', 'Re: React', 'Re:Re: React']; ReactDOM.render( , document.getElementById('root') );

Example 4: conditional rendering react

import React, { Component } from 'react';

// @params [] * denotes optional param (we will need to use conditional rendering for some of these)
// [type](Bulma CSS class): Hero type, focuses on the base styling
// size(Bulma CSS Class): The size of the hero, small, medium, large, etc...
// heading: The main heading
// [subheading]: The subheading if desired
// [alignment](Bulma CSS Class): Aligns the content horizontally

// This Simple HeroComponent is bases upon the following
// https://bulma.io/documentation/layout/hero/ 

export class HeroComponent extends Component
{
	render() {
		return (
          	// The following ternary simply applies a class if it has been specified
			
// Again, another ternary applying a class... blah blah blah....

{this.props.heading}

// So, to answer the question... // The following is one way to do conditional rendering, probably the simplest and cleanest // If this.props.subheading exists, render

{this.props.subheading &&

{this.props.subheading}

}
) } }

Tags:

Misc Example