An iterator function or language struct which can be used to iterate over arrays or lists.
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.
jQuery.each( array, callback )
// or
jQuery.each( object, callback )
