class component vs functional component react code example

Example 1: class app extends component syntax

class Welcome extends React.Component {
  render() {
    return <h1>Hello, {this.props.name}</h1>;
  }
}

Example 2: 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 3: react functional components

const component = () => {
console.log("This is a functional Component");
}

Example 4: create functional component react

import React from 'react'; const App = () => {  const greeting = 'Hello Function Component!';   return <Headline value={greeting} />;}; const Headline = ({ value }) =>  <h1>{value}</h1>; export default App;

Example 5: class to functional component react

// convert a class component to a functional component
class MyComponent extends React.Component {
	state: { 
      name: 'Bob' 
    }
	render() {
      return (
        <p>Hello, my name is {this.state.name}</p>
      );
    }
}

const MyComponent = () => {
  const [name, setName] = React.useState('Bob');
  return (<p>Hello, my name is {name}</p>);
}