[RESOLVED] Definition for Abstraction

[eranga262154]

Hi,

I'm confusing with concept "Abstraction". I go through few articles on the web and consider it as follows.

"Abstraction is a process which software developer consider about an object in terms of its functionality. No need to worry about its implementing details"

Can you guys comment on this?

[Mutuz]

Hi eranga!
You may think of abstraction as a way of making good documentation for your methods, before implementing them.

Say you write some code, and someone else is to change it! It would be optimal for this other person that your methods is well documented, so that he/she does not have to sit down and study your code. It will save him/her some time, right?

With the use of procedural abstraction, you specify each method clearly before you implement it. By specifying post- and preconditions, as well as the method's parameters, others will be able to use the method without studying the implementation. In fact, you do this every time you use a method from the Java API. Have you ever looked at the code for 'println()' or 'sqrt'?!

So, in shorter terms, you have to find out what your methods are going to do, before you think of how they are going to do it.

[eranga262154]

Dear Mutuz,
How nice your comment. Thanks a lot.

You said that APIs are doing this. I mean, everyone can used those APIs without worring about its implimentation. Isn't it?

[Mutuz]

You said that APIs are doing this. I mean, everyone can used those APIs without worring about its implimentation. Isn't it?

Yes, you have learned how to use certain methods by reading the API. This is because the API describes the methods/classes so well, that you don't have to look at it's code.

[eranga262154]

Ok thanks Mutuz, Now i got the point.

[eranga262154]

If I want to look-at APIs code what should I do?

[ComputerJy]

Abstraction

To take a look at the API code, unzip the "src.zip" file in the JDK folder, it has all java source code

[eranga262154]

Thanks for your link on wikipedia. I also refer the same page.