/Javascript/React/React tutorial componentDidMount() componentWillUnmount()

React tutorial componentDidMount() 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>Hello, world!</h1>
        <h2>It is {this.state.date.toLocaleTimeString()}.</h2>
      </div>
    );
  }
}

ReactDOM.render(
  <Clock />,
  document.getElementById('root')
);

Source: reactjs.org

Similar codes

1 vote192 views1 answer
External script in react
Javascript React
6 votes149 views2 answers
React native socket io
Javascript React
0 vote196 views1 answer
Expo cli vs react native cli
Javascript React
16 votes132 views1 answer
How to insern an image in react
Javascript React
0 vote183 views1 answer
Floating button react
Javascript React
-1 vote569 views1 answer
This can also happen when the JS bundle is corrupt or there is an early initialization error when loading React Native.
Javascript React
7 votes169 views1 answer
How to place a line break in react native
Javascript React
-2 votes163 views2 answers
Import link react
Javascript React
0 vote175 views1 answer
React native map not loading
Javascript React
1 vote195 views2 answers
What is the purpose of the super(props) method in React
Javascript React