home *** CD-ROM | disk | FTP | other *** search
- Newsgroups: comp.databases.theory
- From: fred@genesis.demon.co.uk (Lawrence Kirby)
- Path: sparky!uunet!pipex!demon!genesis.demon.co.uk!fred
- Subject: Re: Data abstraction v/s information hiding
- Distribution: world
- References: <DAVIDM.93Jan6115747@consilium.com>
- Organization: BT
- X-Mailer: Simple NEWS 1.90 (ka9q DIS 1.19)
- Lines: 32
- Date: Wed, 13 Jan 1993 00:15:34 +0000
- Message-ID: <726884134snz@genesis.demon.co.uk>
- Sender: usenet@demon.co.uk
-
- In article <DAVIDM.93Jan6115747@consilium.com> davidm@consilium.com writes:
-
- >>>>>> On 22 Dec 92 18:22:20 GMT, yab@cs.brown.edu (Yashesh Bhatia) said:
- >
- >> Data Abstraction & information hiding
- >
- >> Data abstraction, I feel is the hiding of the low level implentation of the
- >> data structure from the operations that are performed on it.
- >
- >> I am not really sure as to what information hiding is, seems to be similar.
- >
- >Your definition for data abstraction is actually much better as a definition
- >for information hiding. Data abstraction is more of a process of finding
- >similarities in the definition of two separate data items and reorganizing the
- >items so that both could take advantage of the same definition for those
- >similarities (ie. instead of two similar definitions, there would be only one
- >defintion). People might claim that you can do data abstraction when you only
- >have one item, but this is only preparing the one item for another TBD item
- >that will take advantage of the abstraction.
-
- I think the original definition is much closer. Abstraction is simply stripping
- an entity down to its behaviour and ignoring the details of implementation.
- Abstraction applies to one entity - it has nothing to do with combining more
- than one entity. It is close to it's English dictionary definition (an
- example of) which is
-
- "process of stripping an idea of its concrete accompaniments"
-
- -----------------------------------------
- Lawrence Kirby | fred@genesis.demon.co.uk
- Wilts, England | 70734.126@compuserve.com
- -----------------------------------------
-