react class component

 import React from 'react';

import ReactDOM from 'react-dom';

const index = 0;

class Clock extends React.Component {

  render() {

    return(

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

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

      </h1>

    );

  }

}

ReactDOM.render(<Clock locale="bn-BD" />, document.getElementById('root'));