react javascript tutorial code example

Example 1: react tutorial

class Board extends React.Component {
  constructor(props) {    super(props);    this.state = {      squares: Array(9).fill(null),    };  }
  renderSquare(i) {
    return <Square value={i} />;
  }

Example 2: React js tutorial

npx create-react-app my-app
cd my-app
cd src

# If you're using a Mac or Linux:
rm -f *

# Or, if you're on Windows:
del *

# Then, switch back to the project folder
cd ..

Example 3: react tutorial

As far as I can tell from looking, codecademy, w3schools, 
and many answers on stack overflow are all outdated.

The best option is "https://reactjs.org/"

Example 4: react quick tutorial

ReactDOM.render(  
    <Hello />,   
    document.getElementById("root")  
);