I have watched a couple videos on JavaScript where the presenter mentioned "caching" a variable but I didn't see them do anything in the code that would "cache" it beyond normal assignments. When I think of cache I think of something stored in local memory in which case aren't all JavaScript variables cached by definition.
When you cache a variable in JavaScript what are you "doing" to it?
EDIT:
I have heard the term in several but the only one that comes to mind is Writing Modular JavaScript – Tutorial. Which I just watched last night. I didn't post it because you have to pay to view and I hate feeling liking I am plugging a pay service on StackExchange.
Best Answer
From this tutorial on efficient javascript:
and
With JavaScript object caching, the number of lookups is cutdown, since the object reference is held within the variable - potentially improving performance and memory usage.