jQuery()

Return a collection of matched elements either found in the DOM based on passed argument(s) or created by passing an HTML string.

.closest()

For each element in the set, get the first element that matches the selector by testing the element itself and traversing up through its ancestors in the DOM tree.

.next()

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

.find()

Get the descendants of each element in the current set of matched elements, filtered by a selector, jQuery object, or element.

jQuery.grep()

Finds the elements of an array which satisfy a filter function. The original array is not affected.

callbacks.has()

Determine whether or not the list has any callbacks attached. If a callback is provided as an argument, determine whether it is in a list.