react js class 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: create react component class

class MyComponent extends React.Component{
    constructor(props){
        super(props);
    };
    render(){
        return(
            <div>
              <h1>
              	My First React Component!
              </h1>
            </div>
        );
    }
};

Example 3: functional component react

function Welcome(props) {
  return <h1>Hello, {props.name}</h1>;
}

function App() {
  return (
    <div>
      <Welcome name="Sara" />      <Welcome name="Cahal" />      <Welcome name="Edite" />    </div>
  );
}

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

Example 4: how to use a js class in react

class Developer {  constructor(firstname, lastname) {    this.firstname = firstname;    this.lastname = lastname;  }   getName() {    return this.firstname + ' ' + this.lastname;  }} class ReactDeveloper extends Developer {  getJob() {    return 'React Developer';  }} var me = new ReactDeveloper('Robin', 'Wieruch'); console.log(me.getName());console.log(me.getJob());