how to get the screen size with JS code example

Example 1: js window dimensions

// better than using window.innerWidth / window.innerHeight 
// because of scrollbars
const client = {
      width: document.documentElement.clientWidth,
      height: document.documentElement.clientHeight
}

Example 2: java script find screen size of device

// Size of browser viewport.
$(window).height();
$(window).width();

// Size of HTML document (same as pageHeight/pageWidth in screenshot).
$(document).height();
$(document).width();