The componentDidMount()
is initiated right after the component is rendered in the DOM. It is called only once so API calls statements are written inside the componentDidMount()
and other functions that requires the component to be rendered in the DOM first are called here.
componentDidMount(){
functions here....
}
class Example extends React.Component {
constructor(props) {
super(props);
this.state = {name: "John"};
}
componentDidMount() {
//change state after 1 second
setTimeout(() => {
this.setState({name: "Billy"})
}, 1000)
}
render() {
return (
<h1>My name is {this.state.name}</h1>
);
}
}
Here, the state name
is changed 1 second after the component renders.