what is the next after comma in $('.elem',elem)?

Question

I'm using code like $('.elem',elem), $('.elem',elem).tabs().

$(".elem") is used to select elements with that class.

But what is the next after comma? What is the use of it?

Answer 1

$('.elem',elem) is $(elem).find('.elem'). In fact, that's what jQuery does with it under the covers. It finds all elements with class "elem" that are descendants of the elem element.

This is covered in the API documentation. It's well worth spending an hour just reading that from beginning to end. There are all sorts of useful things in there that aren't well known. :-) (I'm not saying this is one of them [I'm not a fan of it myself, some folks are], just that generally there are lots of useful things in there.)

Answer 2

This is the context into which the search is done.

It's the same than

$(elem).find('.elem')

See documentation here