answer from Huiqi

[Huiqi]

@interface Rectangle: NSObject
{
   int width;
   int height;
}
-(void) setWidth: (int) w;
-(void) setHeight: (int) h;
-(int) width;
-(int) height;
-(int) area;
-(int) perimeter;
@end

@implementation Rectangle
-(void) setWidth: (int) w
{
   width = w;
}
-(void) setHeight: (int) h
{
   height = h;
}
-(int) width
{
   return width;
}
-(int) height
{
   return height;
}
-(int) area
{
   return width*height;
}
-(int) perimeter
{
   return 2*(width+height);
}
@end
   

#import <Foundation/Foundation.h>

int main (int argc, const char * argv[]) {
    NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init];
   Rectangle *rect1 = [[Rectangle alloc] init];

    // insert code here...
   
   [rect1 setWidth: 4];
   [rect1 setHeight: 3];
   
    NSLog(@"area = %i, perimeter = %i", [rect1 area],[rect1 perimeter]);
    [rect1 release];
   [pool drain];
    return 0;
}

[skochan]

Looks good, Huiqi!

Now rewrite it to use the @property directive, synthesize your accessor methods, and use the dot operator.

Cheers,

Steve Kochan