react native conditional rendering
class Component extends React.Component {
const a = true
render() {
return (
<Container>
{a == true
? (<Button/>)
: null
}
</Container>
)
}
}
This is staying: if a == true, render a button component.
Otherwise render null, in other words nothing.how to use if else inside jsx in react
renderElement(){
if(this.state.value == 'news')
return <Text>data</Text>;
return null;
}
render() {
return (
<View style={styles.container}>
{ this.renderElement() }
</View>
)
}ternary react
render() {
const isLoggedIn = this.state.isLoggedIn;
return (
<div>
The user is <b>{isLoggedIn ? 'currently' : 'not'}</b> logged in.
</div>
);
}conditional props react
// single prop
propName={ condition ? something : somethingElse }
propName={ condition && something }
// multiple props
{ ...( condition ? { ...setOfProps } : { ...setOfOtherProps })}
{ ...( condition && { ...setOfProps })}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
<section className={"hero" + (this.props.type ? " " + this.props.type + " " : " ") + this.props.size}>
<div className="hero-body">
// Again, another ternary applying a class... blah blah blah....
<div className={"container" + this.props.alignment ? " " + this.props.alignment : ""}>
<h1 className="title">{this.props.heading}</h1>
// 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 <h2 .. />
{this.props.subheading && <h2 className="subtitle">{this.props.subheading}</h2>}
</div>
</div>
</section>
)
}
}conditional rendering react
function Mailbox(props) {
const unreadMessages = props.unreadMessages;
return (
<div>
<h1>Hello!</h1>
{unreadMessages.length > 0 && <h2> You have {unreadMessages.length} unread messages. </h2> } </div>
);
}
const messages = ['React', 'Re: React', 'Re:Re: React'];
ReactDOM.render(
<Mailbox unreadMessages={messages} />,
document.getElementById('root')
);Copyright © 2021 Codeinu
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