javascript - Get viewport/window height in ReactJS

Question

How do I get the viewport height in ReactJS? In normal JavaScript I use

window.innerHeight()

but using ReactJS, I'm not sure how to get this information. My understanding is that

ReactDOM.findDomNode()

only works for components created. However this is not the case for the document or body element, which could give me height of the window.

Answer 1

Using Hooks (React 16.8.0+)

Create a useWindowDimensions hook.

import { useState, useEffect } from 'react';

function getWindowDimensions() {
  const { innerWidth: width, innerHeight: height } = window;
  return {
    width,
    height
  };
}

export default function useWindowDimensions() {
  const [windowDimensions, setWindowDimensions] = useState(getWindowDimensions());

  useEffect(() => {
    function handleResize() {
      setWindowDimensions(getWindowDimensions());
    }

    window.addEventListener('resize', handleResize);
    return () => window.removeEventListener('resize', handleResize);
  }, []);

  return windowDimensions;
}

And after that you'll be able to use it in your components like this

const Component = () => {
  const { height, width } = useWindowDimensions();

  return (
    <div>
      width: {width} ~ height: {height}
    </div>
  );
}

Working example

Original answer

It's the same in React, you can use window.innerHeight to get the current viewport's height.

As you can see here