jQuery.each()

A generic iterator function, which can be used to seamlessly iterate over both objects and arrays. Arrays and array-like objects with a length property (such as a function’s arguments object) are iterated by numeric index, from 0 to length-1. Other objects are iterated via their named properties.

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.