React class

 import React from 'react';

import ReactDOM from 'react-dom';

const index = 0;

class Clock{

  print() {

    return(

      <h1 className='heading' tabIndex={index}>

        <span className='text'>Hello {new Date().toLocaleTimeString()}</span>

      </h1>

    );

  }

}

const ClockComponent = new Clock();

ReactDOM.render(ClockComponent.print(), document.getElementById('root'));