conditional rendering functional component code example
Example 1: if else render react
render() {
const isLoggedIn = this.state.isLoggedIn;
return (
<div>
{isLoggedIn ? (
<LogoutButton onClick={this.handleLogoutClick} />
) : (
<LoginButton onClick={this.handleLoginClick} />
)}
</div>
);
}
Example 2: 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>
)
}
Example 3: 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.
Example 4: ternary react
render() {
const isLoggedIn = this.state.isLoggedIn;
return (
<div>
The user is <b>{isLoggedIn ? 'currently' : 'not'}</b> logged in.
</div>
);
}
Example 5: conditional props react
propName={ condition ? something : somethingElse }
propName={ condition && something }
{ ...( condition ? { ...setOfProps } : { ...setOfOtherProps })}
{ ...( condition && { ...setOfProps })}
Example 6: 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')
);