check screen width js code example
Example 1: javascript screen size
var w = window.innerWidth;
var h = window.innerHeight;
Example 2: get screen width javascript
window.screen.width
//or just
screen.width
Example 3: get the size of the screen javascript
window.screen.height;
window.screen.width;
Example 4: js know size of screen
alert("Your screen resolution is: " + screen.width + "x" + screen.height)