Using jQuery To Get Size of Viewport

Solution 1:

To get the width and height of the viewport:

var viewportWidth = $(window).width();
var viewportHeight = $(window).height();

resize event of the page:

$(window).resize(function() {

});

Solution 2:

You can try viewport units (CSS3):

div { 
  height: 95vh; 
  width: 95vw; 
}

Browser support

Solution 3:

1. Response to the main question

The script $(window).height() does work well (showing the viewport's height and not the document with scrolling height), BUT it needs that you put correctly the doctype tag in your document, for example these doctypes:

For HTML 5:

<!DOCTYPE html>

For transitional HTML4:

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

Probably the default doctype assumed by some browsers is such, that $(window).height() takes the document's height and not the browser's height. With the doctype specification, it's satisfactorily solved, and I'm pretty sure you peps will avoid the "changing scroll-overflow to hidden and then back", which is, I'm sorry, a bit dirty trick, specially if you don't document it on the code for future programmer's usage.

2. An ADDITIONAL tip, note aside: Moreover, if you are doing a script, you can invent tests to help programmers in using your libraries, let me invent a couple:

$(document).ready(function() {

      if(typeof $=='undefined') {
        alert("PROGRAMMER'S Error: you haven't called JQuery library");
      } else if (typeof $.ui=='undefined') {
        alert("PROGRAMMER'S Error: you haven't installed the UI Jquery library");
      }
      if(document.doctype==null || screen.height < parseInt($(window).height()) ) {
        alert("ERROR, check your doctype, the calculated heights are not what you might expect");
      } 

});


EDIT: about the part 2, "An ADDITIONAL tip, note aside": @Machiel, in yesterday's comment (2014-09-04), was UTTERLY right: the check of the $ can not be inside the ready event of Jquery, because we are, as he pointed out, assuming $ is already defined. THANKS FOR POINTING THAT OUT, and do please the rest of you readers correct this, if you used it in your scripts. My suggestion is: in your libraries put an "install_script()" function which initializes the library (put any reference to $ inside such init function, including the declaration of ready()) and AT THE BEGINNING of such "install_script()" function, check if the $ is defined, but make everything independent of JQuery, so your library can "diagnose itself" when JQuery is not yet defined. I prefer this method rather than forcing the automatic creation of a JQuery bringing it from a CDN. Those are tiny notes aside for helping out other programmers. I think that people who make libraries must be richer in the feedback to potential programmer's mistakes. For example, Google Apis need an aside manual to understand the error messages. That's absurd, to need external documentation for some tiny mistakes that don't need you to go and search a manual or a specification. The library must be SELF-DOCUMENTED. I write code even taking care of the mistakes I might commit even six months from now, and it still tries to be a clean and not-repetitive code, already-written-to-prevent-future-developer-mistakes.