实现Square类,让其继承自Rectangle类,并在Square类增添新属性和方法
1 #import <Foundation/Foundation.h> 2 3 @interface Rectangle : NSObject{ 4 int width; 5 int height; 6 } 7 @property int width,height; 8 -(int) area; 9 -(int) perimeter; 10 -(void)setWidth:(int)w andHeight:(int)h; 11 12 @end 13 14 15 #import "Rectangle.h" 16 17 @implementation Rectangle 18 @synthesize width,height; 19 -(void)setWidth:(int)w andHeight:(int) h{ 20 width=w; 21 height=h; 22 } 23 -(int) area{ 24 return width*height; 25 } 26 -(int) perimeter{ 27 return (width+height)*2; 28 } 29 30 @end 31 32 33 34 #import <Foundation/Foundation.h> 35 #import "Rectangle.h" 36 @interface Square : Rectangle 37 -(void) setSide:(int) s; 38 -(int)side; 39 -(int)area; 40 -(int)perimeter; 41 42 @end 43 44 45 #import "Square.h" 46 47 @implementation Square 48 49 -(void) setSide:(int) s{ 50 [self setWidth:s andHeight:s]; 51 } 52 53 -(int) side{ 54 return width; 55 } 56 57 -(int)area{ 58 return width*width; 59 } 60 61 -(int)perimeter{ 62 return 2*(width+height); 63 } 64 @end