Display the matched elements by fading them to opaque.
Hide the matched elements by fading them to transparent.
Adjust the opacity of the matched elements.
Display or hide the matched elements by animating their opacity.
Selects all elements of type file.
Reduce the set of matched elements to those that match the selector or pass the function's test.
Get the descendants of each element in the current set of matched elements, filtered by a selector, jQuery object, or element.
Selects the first matched element.
Reduce the set of matched elements to the first in the set.
Selects all elements that are the first child of their parent.
Selects element if it is currently focused.
Bind an event handler to the "focusin" event.