The
componentDidMount()
format of the method is as follows:
componentDidMount()
componentDidMount()
method is called immediately after the component is mounted (inserted into the DOM tree).
Initialization that depends on the DOM node should be placed in the
componentDidMount()
in the method.
The following example outputs first
runoob
and then use the
componentDidMount()
method is set to output after the component is mounted
google
: 3.16.1. Example ¶
classHeaderextendsReact.Component{constructor(props){super(props);this.state={favoritesite:"runoob"};}componentDidMount(){setTimeout(()=>{this.setState({favoritesite:"google"})},1000)}render(){return(<h1>My favorite website is{this.state.favoritesite}</h1>);}}ReactDOM.render(<Header/>,document.getElementById('root'));