CPSC 210
D8: Advanced Iterators
Learning Goals
-
To apply the Iterator Design Pattern to a given problem
- in the case where you need to design your own iterator class.
The Iterator Pattern
Image source: https://refactoring.guru/
- Your class needs to implement Iterable<E>
- Your class returns a home-made iterator when iterator() is called
- Your iterator...
- ...must implement Iterator<E>
- ...must have a counter that keeps track where it is
- ...must implement hasNext() and next()
Your own iterator
Iterator Hierarchy
Iterable<E>
Iterator<E> iterator()
<<interface>>
Iterator<E>
boolean hasNext()
E next()
void remove()
<<interface>>
returns new MyCollectionIterator<E>()MyCollection<E>
Iterator<E> iterator()
MyCollectionIterator<E>
