componentDidUpdate
componentDidUpdate(prevProps, prevState) {
if (prevState.pokemons !== this.state.pokemons) {
console.log('pokemons state has changed.')
}
}componentDidUpdate
componentDidUpdate(prevProps, prevState) {
if (prevState.pokemons !== this.state.pokemons) {
console.log('pokemons state has changed.')
}
}componentWillUnmount
class Clock extends React.Component {
constructor(props) {
super(props);
this.state = {date: new Date()};
}
componentDidMount() {
this.timerID = setInterval(
() => this.tick(),
1000
);
}
componentWillUnmount() {
clearInterval(this.timerID);
}
tick() { this.setState({ date: new Date() }); }
render() {
return (
<div>
<h1>Bonjour, monde !</h1>
<h2>Il est {this.state.date.toLocaleTimeString()}.</h2>
</div>
);
}
}
ReactDOM.render(
<Clock />,
document.getElementById('root')
);shouldcomponentupdate
shouldComponentUpdate(nextProps, nextState) {
return true;
}lifecycles if reactjs
class Clock extends React.Component {
constructor(props) {
super(props);
this.state = {date: new Date()};
}
componentDidMount() { }
componentWillUnmount() { }
render() {
return (
<div>
<h1>Hello, world!</h1>
<h2>It is {this.state.date.toLocaleTimeString()}.</h2>
</div>
);
}
}component did mmount
componentDidUpdate(prevProps, prevState, snapshot)react lifecycle hooks
class Content extends React.Component {
// ...
componentWillMount() {
this.setState({ activities: data });
}
// ...
}Copyright © 2021 Codeinu
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