[React] Button and Label Example

class Button extends React.Component {
	render() {
  	return(
    	<button onClick={this.props.onClickFunction}>
      	Plus One
      </button>
    )
  }
}

class Text extends React.Component {
	render() {
  	return(
    	<div>
      	{this.props.display}
      </div>
    )
  }
}

class App extends React.Component {
	state = {counter : 0};
  incrementCounter = () => {
  	this.setState((prevState) => {
    	return {
      	counter: prevState.counter + 1
      }
    })
  }
	render() {
  	return(
    	<div>
      	<Button onClickFunction = {this.incrementCounter}/>
        <Text display = {this.state.counter}/>
      </div>
    )
  }
}

ReactDOM.render(<App />, mountNode)