text: import React from 'react';
  export default class WindowDimensions extends React.Component {
      constructor(props){
        super(props);
        this.updateDimensions = this.updateDimensions.bind(this);
      }
       
      componentWillMount() {
        this.updateDimensions()
      }
    
      componentDidMount() {
        window.addEventListener('resize', this.updateDimensions)
      }
    
      componentWillUnmount() {
        window.removeEventListener('resize', this.updateDimensions)
      }
    
      updateDimensions() {
        this.setState({width: window.innerWidth, height: window.innerHeight})
      }
    
      render() {
        return <span>{this.state.width} x {this.state.height}</span>
      }
    }