React

by Nihar Raote

HTML

<script src="https://cdnjs.cloudflare.com/ajax/libs/react/17.0.2/umd/react.production.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/react-dom/17.0.2/umd/react-dom.production.min.js"></script>
<div id="app"></div>

CSS

body {
  background: #20262E;
  padding: 20px;
  font-family: Helvetica;
}

#app {
  background: #fff;
  border-radius: 4px;
  padding: 20px;
  transition: all 0.2s;
}

li {
  margin: 8px 0;
}

h2 {
  font-weight: bold;
  margin-bottom: 15px;
}

.done {
  color: rgba(0, 0, 0, 0.3);
  text-decoration: line-through;
}

input {
  margin-right: 5px;
}

React

const { useRef } = require('React')

const App = () => {
	let secondInput = useRef(null);
  
  function btnClickHandler(){
  	console.log("hello");
  	secondInput.current.focus();
  }
  
	return (
  	<div>
  	  <h1>Hello</h1>
      <input id="first" />
      <input id="second" ref={secondInput} />
      <button onClick="btnClickHandler">Click here</button>
  	</div>
  )
}

ReactDOM.render(<App />, document.querySelector("#app"))