[jQuery] Testing if a .data('key') is defined?
I'm using .data to store some information and occasionally hit a case
where I'll try to do something with the stored data and will get an
error e.g., $("#foo").data("bar") is undefined.
I need to fix my code so that doesn't happen, but would like to know
the best way to test if "bar" has been defined for $("#foo") so that I
can catch these errors before they happen.