oneway.js

class OneWayComponent extends React.Component {
  constructor() {
    super()
    this.state = { name: 'Hoang' }
  }
  change(event) {
    this.setState({ name: event.target.value });
  }
  render() {
    return (
      <div>
        <input value={ this.state.name } onChange={ (event)=> this.change(event) } />
        <p>Hello { this.state.name }!</p>
      </div>
    );
  }
}