tutorial react js code example

Example 1: react tutorial for beginners

import React from 'react';

class App extends React.Component {
   constructor(props) {
      super(props);
      
      this.state = {
         data: 'Initial data...'
      }
      this.updateState = this.updateState.bind(this);
   };
   updateState() {
      this.setState({data: 'Data updated...'})
   }
   render() {
      return (
         

            CLICK
            
{this.state.data}
         
      );
   }
}
export default App;

Example 2: react tutorial

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

Example 3: react tutorial

renderSquare(i) {
    return ;
  }

Example 4: 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 5: react quick tutorial

ReactDOM.render(  
    ,   
    document.getElementById("root")  
);