change react app code example

Example 1: setstate react js

constructor(props) {
        super(props);
        this.state = {
            isActive: true,
        };
    }

    checkStatus = () => {
        this.setState({		// use this function
            'isActive' : !this.state.isActive,
        });
    }

Example 2: react lifecycle hooks

class ActivityItem extends React.Component {
  render() {
    const { activity } = this.props;

    return (
      <div className='item'>
        <div className={'avatar'}>
          <img
            alt='avatar'
            src={activity.actor.avatar_url} />
        </div>

        <span className={'time'}>
          {moment(activity.created_at).fromNow()}
        </span>
        
        <p>{activity.actor.display_login} {activity.payload.action}</p>
        <div className={'right'}>
          {activity.repo.name}
        </div>
      </div>
    )
  }
}