Very Basic Objective-C issue, I am sure

Question

So I picked up a book on ojective-c namely Mr. Kochan's, and have been trying to work through the exercises and examples. I ran into my first problem that I haven't been able to solve myself. The error says that the object I tried to create "point" is being redeclared as a different type of symbol. Although I can swear I have the section from the book copied almost verbatim, I am sure I am doing something overtly wrong, but I still can't find it. Any suggestions would be greatly appreciated.
Thanks in advance!
Here is the code I am working with sans the header:
#import <stdio.h>
#import <objc/Object.h>
//--------------Interface Section----------
@interface Point: Object
int hcoord;
int vcoord;
-(void) print;
-(void) setHcoord: (int) x;
-(void) setVcoord: (int) y;
@end
//-------- Implementaion Section-------------
@implementation Point;
-(void) print
printf (" %i,%i", hcoord, vcoord);
-(void) setHcoord: (int) h
hcoord = h;
-(void) setVcoord: (int) v
vcoord = v;
@end
//--------- program section------------
int main (int argc, char *argv[])
Point *point1 = [[Point alloc] init];
[point1 setHcoord: 4];
[point1 setVcoord: 5];
printf ("The cartesian coordinates for point 1 are:");
[point1 print];
printf ("\n");
[point1 free];
return 0;
12" Powerbook   Mac OS X (10.4.7)  

Answer 1

OK. I think I see what's going on. Point is already declared in the Core Foundation, which is included in your project. If you're following the directions on page 10 of Kochan's book, they're kind of out of date.
I can get your program to build and run if I follow these steps:
1. Create a new project in Xcode. But instead of choosing a "Cocoa Application" like the book says, scroll down to the section that says "Command Line Utility". You want a "Foundation Tool".
2. In your "Source" folder in Xcode, you'll see two files, one with ".m" on the end, the other with "Prefix.pch" at the end. Open the ".m" file and replace everything with your code. Close and save the ".m" file.
3. Now, open the other file (the one ending with "_Prefix.pch" in your "Source" folder. There is a comment at the top, then three lines:
<pre class="command">#ifdef _OBJC_
#import <Foundation/Foundation.h>
#endif</pre>Comment out those three lines like so:
<pre class="command">//#ifdef _OBJC_
// #import <Foundation/Foundation.h>
//#endif</pre>Your project should compile and run. Alternatively, since Point is already defined, you can just change the name from Point something else.
Instead of step 3 above, just replace Point with something like MyPoint. Even just changing the "P" to a lower case "p" is enough to fix it.
charlie
P.S. -- If you haven't already visited, I suggest checking out Steve Kochan's page for that book. Pay special attention to the Errata section. There are some errors in the book and the corrections are there, so that's a good resource.