An iterator is a design pattern used in computer programming that provides a way to access the elements of an aggregate object (such as a collection or a container) sequentially without exposing its underlying representation. It acts as a cursor pointing to the current element in a sequence and allows the programmer to traverse through the elements of the collection one by one.
In computing, an iterator typically includes methods to perform the following actions:
Access the current element: An iterator can provide access to the element that it currently points to in the collection.
Move to the next element: It can advance the iterator to point to the next element in the sequence.
Check for the end of the collection: It often includes a way to determine whether all elements have been traversed, commonly through a method that indicates the end of the collection has been reached.
Remove the current element: Some iterators also support the removal of the current element from the collection.
Iterators abstract the process of iterating over a collection, allowing different types of collections (like arrays, lists, trees, etc.) to be accessed using a common interface. This abstraction enables the same piece of code to work with various data structures, enhancing code reusability and flexibility.
In many programming languages, iterators conform to a specific iterator protocol or interface that defines the methods and behavior of the iterator. For example, in Java, the Iterator interface provides methods like hasNext(), next(), and remove(). In Python, the iterator protocol involves the __iter__() and __next__() methods, and in C++, iterators are provided as part of the Standard Template Library (STL) with different iterator c...
