react componen code example

Example 1: class in react

class App extends Component {
    constructor() {
        super()
        this.state = {
            name: "Sally",
            age: 13
        }
    }
    
    render() {
        return (
            <div>
                <h1>{this.state.name}</h1>
                <h3>{this.state.age} years old</h3>
            </div>
        )    
    }
}

Example 2: componentDidUpdate

componentDidUpdate(prevProps, prevState) {
  if (prevState.pokemons !== this.state.pokemons) {
    console.log('pokemons state has changed.')
  }
}

Example 3: react component

/* React Component Template */
export default class MyComponent extends React.Component {
  constructor(props) {
    super(props);
	this.state = {
		//state properties here
	};
  }
  render() {
	return (
		<div></div>
	);
  }
}

Example 4: lifecycle method react

INITIALIZATION= setup props and state 
MOUNTING= constructor->componentWillMount->render->componentDidMount//Birth
UPDATE= shouldComponentUpdate->componentWillUpdate->render
  		->componentDidUpdate //Growth
UNMOUNTING= componentWillUnmount //Death

Example 5: React Components

class Car extends React.Component {
  render() {
    return <h2>Hi, I am a Car!</h2>;
  }
}

Example 6: react lifecycle

constructor(props) {
  super(props);
  // Don't call this.setState() here!
  this.state = { counter: 0 };
  this.handleClick = this.handleClick.bind(this);
}