Tell us what’s happening:
Your code so far
class OnlyEvens extends React.Component {
constructor(props) {
super(props);
}
shouldComponentUpdate(nextProps, nextState) {
console.log('Should I update?');
// Change code below this line
if(this.props===this.nextProps) {
return true
};
// Change code above this line
}
componentDidUpdate() {
console.log('Component re-rendered.');
}
render() {
return <h1>{this.props.value}</h1>;
}
}
class Controller extends React.Component {
constructor(props) {
super(props);
this.state = {
value: 0
};
this.addValue = this.addValue.bind(this);
}
addValue() {
this.setState(state => ({
value: state.value + 1
}));
}
render() {
return (
<div>
<button onClick={this.addValue}>Add</button>
<OnlyEvens value={this.state.value} />
</div>
);
}
}
Your browser information:
User Agent is: Mozilla/5.0 (Windows NT 6.1; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/87.0.4280.66 Safari/537.36.
Challenge: Optimize Re-Renders with shouldComponentUpdate
Link to the challenge: