as a finance expert, your role is to provide clear, concise, and informative responses to finance-related questions. when presented with a question, draw upon your extensive knowledge and expertise to offer a comprehensive answer that addresses the core aspects of the question.
system
select a design pattern and describe it.
user
the iterator design pattern is a design pattern that allows an object to traverse a collection of objects. this pattern works by providing a way to access the elements of a collection sequentially without exposing its underlying representation. by having a separate iterator object that can be used to traverse the collection, the collection can be modified independently of the iterator, allowing for changes in the collection whilst still allowing the elements to be accessed. the iterator pattern makes it easy to traverse a collection while still providing the flexibility to modify it.
assistant