什么是实现集合在VB6？ [英] What Are Collections Implemented As In VB6?
问题描述
因此，VB6中的集合会跟踪每个对象的键，您可以通过键来查找对象。
这意味着集合被实现为某种类型的hashtable在引擎盖下？我意识到你可以有一个集合中的同一个键的多个项目，因此SOME SORT。
任何人都知道VB6集合应该代表什么类型的数据结构？
据我所知，VBA集合被实现为链表（由Integer索引和For Each ... Next使用）和哈希表（由键使用）。
b $ b @MarkJ：我应该给出我的引用：
Hardcore Visual Basic 2nd Ed。作者：Bruce McKinney，由Microsoft Press出版1997 ISBN 1-57231-422-2
行情：
191 - 集合类
简单来说，Collection类是CList类[...]的C ++版本，事实上，如果你将CList增强为一个双向链表，并给它一些更多的功能（也许使用一个哈希表来查找字符串键），你将有一个集合类，类似于Visual Basic提供的类。
事实上，Visual Basic开发人员告诉我是双重链接的列表（具有支持索引的额外功能）。
现在，McKinney更像是一个记者而不是程序员，而不是开发人员。但是，他为微软工作，在VB和VBA团队有联系人。他的解释对我有用。
顺便说一下，双向链表的原因是让它在集合的开始和结尾都有效地插入项目。 / p>
So a collection in VB6 keeps track of a key for each object, and you can look up the object by its key.
Does that mean collections are implemented as some sort of hashtable under the hood? I realize you can have multiple items with the same key in a collection, hence the SOME SORT.
Anybody know what type data structure a VB6 collection is supposed to represent?
As far as I know, the VBA Collection is implemented as a linked list (used by Integer indexes and For Each...Next) and a hash table (used by keys). And as Raven said, you can't have multiple items with the same key.
Edited:
@MarkJ: I should have given my cite for this: Hardcore Visual Basic 2nd Ed. by Bruce McKinney, published by Microsoft Press 1997 ISBN 1-57231-422-2
Quotes:
Page 191 - The Collection Class
"To put it simply, the Collection class is a souped-up C++ version of the CList class [...]. In fact, if you enhance CList to be a doubly linked list and give it a few more features (and perhaps use a hash table to look up string keys), you'll have a collection class much like the one provided with Visual Basic."
Page 197 - Performance
"And, as a matter of fact, I have been told by Visual Basic developers that Collections are doubly linked lists (with additional features to support indexing)."
Now, McKinney was more of a journalist than a programmer, and not a developer. However, he did work for Microsoft, and have contacts in the VB and VBA teams. His explanation works for me.
Incidentally, the reason for the doubly-linked list is to make it efficient to insert items at both the beginning and end of the collection.
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