Aaron Gustafson is the founder and principal consultant of Easy! Designs, a web development boutique. He is also a manager of the Web Standards Project (WaSP).
I remember being able to check for a particular jQuery version by doing the following:
function someFunction(){
if( typeof( jQuery ) == 'undefined' ||
parseFloat( jQuery.jquery ) < 1.2 ) return;
// code that uses jQuery 1.2 or higher
}
That functionality doesn't appear to work anymore because the jQuery version is not (at least based on my exploration of the object) exposed anymore. I'm not sure if that changed in 1.3 or 1.4, but for many of us developing jQuery add-ons, it's nice to be able to throw an error if the version we want/need is not available.