lifecycle of a component code example
Example 1: react lifecycle example
class Test extends React.Component {
constructor() {
console.log('Constructor')
super();
this.state = {
count: 0
};
}
componentDidMount() {
console.log("component did mount");
}
componentDidUpdate() {
console.log("component did update");
}
onClick = () => {
this.setState({ count: this.state.count + 1 });
};
render() {
console.log("render");
return (
<div>
Hello Test
<button onClick={this.onClick}>
{this.state.count}
</button>
</div>
);
}
}
//--for first time
//Constructor
//render
//component did mount
//--for any update
//render
//component did update
Example 2: Component life cycle
class LifeCycle extends React.Component {
constructor(props)
{
super(props);
this.state = {
date : new Date(),
clickedStatus: false,
list:[]
};
}
componentWillMount() {
console.log('Component will mount!')
}
componentDidMount() {
console.log('Component did mount!')
this.getList();
}
getList=()=>{
/*** method to make api call***
fetch('https://api.mydomain.com')
.then(response => response.json())
.then(data => this.setState({ list:data }));
}
shouldComponentUpdate(nextProps, nextState){
return this.state.list!==nextState.list
}
componentWillUpdate(nextProps, nextState) {
console.log('Component will update!');
}
componentDidUpdate(prevProps, prevState) {
console.log('Component did update!')
}
render() {
return (
<div>
<h3>Hello Mounting Lifecycle Methods!</h3>
</div>
);
}
}