Chapter 8 @property/@synthesize question

[darkslayer13]

Hi - so I was going through chapter 8 thinking that I understood everything from before. Then I came across this code on pg 166:

@interface XYPoint: NSObject
{
      int x; int y;
}
@property int x, y;

-(void) setX: (int) xVal andY: (int) yVal;

@end


I thought when doing the @property and @synthesize statements, the setter and getter methods are created for you. So, why is the following statement part of the interface file, and not only the implementation file?

-(void) setX: (int) xVal andY: (int) yVal;

/////////////////////////////

Also, as a side question:

I couldnt really figure it out, but when do you use pointers like this:

(XYPoint *) origin

instead of this:

XYPoint *origin

[skochan]

First, setX:andY: is not a synthesized method; it is a convenience method that was added to allow you to set two properties with a single method call.  It's an arbitrary addition to the class.

Second, the Objective-C syntax for return values for methods and for arguments to methods requires the object type be enclosed in parentheses.  I don't know why that is, but it is.  

Cheers,

Steve

[darkslayer13]

Wow! Thanks for the quick response! I cant wait for the 3rd ed to come out! Already preordered! 

Cheers,

~Zach