I've come across a fairly obscure problem having to do with measuring a document's height before the styling has been applied by the browser. More information here:

• http://sonspring.com/journal/jquery-iframe-sizing
• http://ajaxian.com/archives/safari-3-onload-firing-and-bad-timing

In Dave Hyatt's comment from June 27, he advises simply checking the document.body.offsetLeft property to force Safari to do a reflow.

Can I simply use the following statement:

document.body.offsetLeft;

or do I need to assign it to a variable, e.g.:

var force_layout = document.body.offsetLeft;

in order for browsers to calculate that value?

I think this comes down to a more fundamental question - that is, without being part of an assignment statement, will JavaScript still evaluate a property's value? Does this depend on whether a particular browser's JavaScript engine optimizes the code?