How to take out the value of X and check if it is greater than 1200?

Question

JavaScript

There is a code that displays the value of the custom screen extension when executed.

var x = 0;

window.addEventListener("resize", function() {
  document.getElementById('widthInner').innerHTML = window.innerWidth;
  x = window.innerWidth;
}, false);

<span id="width">0</span>
You need to set the screen resolution values ​​for the X variable and check if it is greater than 1200. If it is greater, then execute alert('complete').
When I tried to do this, the value just didn't show up.

Answer 1

window.addEventListener("resize", function() {
  x = window.innerWidth;
  return x > 1200 ? alert('complete') : false;
}, false);

Answer 2

https://www.npmjs.com/package/js-media-query
Subscribe to the event and do your thing.
You can see in the source code what and where it comes from.