The Essential Tools Module provides several distinct methods for iterating over a collection class. Most collections offer an apply() member function, which applies your supplied function to every element of a collection class before returning.

Many of the RWCollectable-based collection classes have associated iterator classes. The use of these iterator classes is described in the section Iterators for Collection Classes. The templatized collection classes use the C++ Standard Library-based iterator methods in these classes. The use of these methods is the topic of the remainder of this section.