Mailing Lists: Apple Mailing Lists

Image of Mac OS face in stamp
 
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Is pointer syntax logical?



Why does the declaration of a pointer to an object look like this
  Fraction *aFraction;
instead of like this

  (Fraction *) aFraction;

-----------------
I’m reading Kochan’s book “Programing in Objective-C” and have come across pointers. What confuses me is the syntax associated with pointers. For instance Kochan defines a class called Fraction and uses it in the main program like this:
  Fraction *aFraction = [[Fraction alloc] init];
which I read as “create a Fraction object and let the pointer aFraction of type Fraction point to it”. 

Now if I understand things correctly the above line is equivalent to the following two lines of code
  Fraction *aFraction;
  aFraction = [[Fraction alloc] init];
and not to
  Fraction *aFraction;
  *aFraction = [[Fraction alloc] init];

In the line 
  Fraction *aFraction;
the Fraction is the type and aFraction is a variable. In my mind it seems that the asterisk belongs more to the type Fraction then to the variable aFraction.  

Look at the following line of code:  
  -(Fraction *) add: (Fraction *) f 
Here we are declaring a method that takes a fraction object as input and returns a fraction object as output. Here we clearly see that the asterisk belongs more to the type Fraction then to the variable f.

So if I was to define the syntax of C I would rather define the declaration of a pointer like this:
  (Fraction *) aFraction;
But when K&R defined the syntax of C they used (what from my naive point of view doesn’t  seem logical)
  Fraction *aFraction;
So my question is why the syntax for pointers looks like it does. Is there any logical explanation. 

Thanks Bob




       
____________________________________________________________________________________
Moody friends. Drama queens. Your life? Nope! - their life, your story. Play Sims Stories at Yahoo! Games.
http://sims.yahoo.com/
_______________________________________________

Cocoa-dev mailing list (email@hidden)

Please do not post admin requests or moderator comments to the list.
Contact the moderators at cocoa-dev-admins(at)lists.apple.com

Help/Unsubscribe/Update your Subscription:
http://lists.apple.com/mailman/options/cocoa-dev/email@hidden

This email sent to email@hidden



Visit the Apple Store online or at retail locations.
1-800-MY-APPLE

Contact Apple | Terms of Use | Privacy Policy

Copyright © 2007 Apple Inc. All rights reserved.