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}}
)
}
}