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Why is void used?

Vishal Hegde
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Joined: Aug 01, 2009
Posts: 1055

This might sound a bit weird but i really did not get the void concept in book it's given that void is a return type which returns nothing then why to use void?


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Campbell Ritchie
Sheriff

Joined: Oct 13, 2005
Posts: 38045
    
  22
The void keyword is not so much a erturn type as an absence of return type.

It is needed because every method must declare what it returns, or (void) that it returns nothing.
Fidel Edwards
Ranch Hand

Joined: Mar 19, 2008
Posts: 231
Campbell Ritchie wrote:The void keyword is not so much a erturn type as an absence of return type.


Exactly what Campbell says. I just want to give you an example that gives the clear understanding of void. In swing/AWT (It could be true for any other Java frameworks. I tested it in Swing/AWT. So, please conside this). For an analogy, We have simple user login page. In this page we are first checking whether user filled username and password or not? If
No then we will simply put a check

else yes then

  • Create Database Connection
  • Validate User
  • And other related user authentication task


  • So in first check (#1) we say to compiler if something goes wrong then please do not proceed further.

    I think that will be sufficient to explain. In case of any doubt please let me know.


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    Campbell Ritchie
    Sheriff

    Joined: Oct 13, 2005
    Posts: 38045
        
      22
    I would have thought that throwing an Exception would be a better approach than a plain return; statement in that situation.
    Janeice DelVecchio
    Saloon Keeper

    Joined: Sep 14, 2009
    Posts: 1659
        
      11

    I just had to do a whole project that was filled with entry validation. I didn't throw any exceptions, just returned true or false for good or bad. It seems like Ashish had a similar take on a similar problem. I guess now that you say it exceptions might be good, but I think in a beginner or low level school project, probably not necessary.


    When you do things right, people won't be sure you've done anything at all.
    Campbell Ritchie
    Sheriff

    Joined: Oct 13, 2005
    Posts: 38045
        
      22
    If I were marking, I would give extra marks for your using Exceptions to enforce defensive programming.
    John de Michele
    Rancher

    Joined: Mar 09, 2009
    Posts: 600
    I agree with Campbell that exceptions are a much better choice.

    John.
    Fidel Edwards
    Ranch Hand

    Joined: Mar 19, 2008
    Posts: 231
    John de Michele wrote:I agree with Campbell that exceptions are a much better choice.

    John.


    I also agree with Campbell's comments but I just want to give a glimpse of void returning situations. It is always as good practice to handle exception rather than simply writing return.

    Vinod Tiwari
    Ranch Hand

    Joined: Feb 06, 2008
    Posts: 459
        
        1
    Say you senerio where you want to do some action but don't want to have an acknowledgement (read return) you can use a void there.


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    I agree. Here's the link: http://aspose.com/file-tools
     
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