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Today, I would like to share with you the relevant knowledge about what the motivation of web iterator pattern is. The content is detailed and the logic is clear. I believe most people still know too much about this, so share this article for your reference. I hope you can get something after reading this article. Let's take a look at it.

Intention

Provides a unified way to access the elements contained in the aggregate object, regardless of how these elements are managed.

motivation

The so-called aggregate object here refers to the object that contains other elements, and one of its important functions is to manage other objects. Such being the case, it must include the functions of adding elements, deleting elements, and getting elements. Generally speaking, the function of adding and deleting objects is relatively stable and will not change easily. Getting elements is often accompanied by traversal and filtering of elements, which often varies with requirements. This difference may be a difference in the way elements are filtered, or in the direction of traversal, or between exclusive traversal and multiple traversal.

In order to meet these diverse requirements, a common practice is to separate the traversal function of the element from the aggregate object, which is called the iterator pattern. The iterator provides an interface to access and traverse the elements in the aggregate object while managing the current traversal location. In this mode, different iterators can be provided for different requirements without making any changes to the aggregate object.

An iterator is a means for users to access aggregate objects. For users, it is necessary to provide an iterative interface to access data. The functions of this interface include initializing the iterator, iterating, determining whether the iteration is over, and getting the function of the current element. For aggregation objects, iterators need to implement iterative interfaces using the data in the aggregation objects.

When using the iterator pattern, you first need to define a common iterator interface. When using aggregate classes, users are programmed according to this common iterator class interface. On the other hand, the provider of the aggregation class, while implementing the aggregation class, implements an iterator class that is provided to the user together with the aggregation class. In this way, users can use the iterator interface to access the aggregate class in a unified way.

That's all of the article "what is the motivation for the web iterator pattern?" Thank you for reading! I believe you will gain a lot after reading this article. The editor will update different knowledge for you every day. If you want to learn more knowledge, please pay attention to the industry information channel.

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