.is()

Check the current matched set of elements against a selector, element, or jQuery object and return true if at least one of these elements matches the given arguments.

.prev()

Get the immediately preceding sibling of each element in the set of matched elements. If a selector is provided, it retrieves the previous sibling only if it matches that selector.

.data()

Store arbitrary data associated with the matched elements or return the value at the named data store for the first element in the set of matched elements.