Javascript add if width screen

Hello,

I use the following javascript code to make it that my products page shows 4 products in a row instead of 3:

add_filter('loop_shop_columns', 'loop_columns');
if (!function_exists('loop_columns')) {
	function loop_columns() {
		return 3; // 3 products per row
	}
}

This code works well.
However, I only want this to happen when screen width is 1345px or larger. If smaller I just want it to be the standard 3 products per row.

I’ve searched and tried different codes, but each time my website becomes blank.

I found this:

if ( $(window).width() > 1345) {
  //Add your javascript for large screens here
}
else {
  //Add your javascript for small screens here
}

But how to integrate this code into the first code?

Thanks!