典型的继承例子：形状Shape为基类，继承它的类有:点类Point、圆类Circle、球体类Sphere、矩形类Rectangle、正方形类Square
点类Point也为基类，继承它的类有：圆类Circle、球体类Sphere、矩形类Rectangle、正方形类Square
圆类Circle也为基类，继承它的类有：球体类Sphere
矩形类Rectangle为基类，继承它的类是：正方形类Square
//Shape类 .h和.m文件
1 // Shape.h 2 // 继承 3 // 4 // Created by ma c on 15/8/11. 5 // Copyright (c) 2015年. All rights reserved. 6 // 形状类 7 8 #import <Foundation/Foundation.h> 9 10 @interface Shape : NSObject 11 @property(nonatomic,assign)CGFloat length; 12 @property(nonatomic,assign)CGFloat area; 13 @property(nonatomic,assign)CGFloat volum; 14 -(void)draw; 15 -(void) Area; 16 -(void) Length; 17 -(void) Volum; 18 @end
1 // Shape.m 2 // 继承 3 // 4 // Created by ma c on 15/8/11. 5 // Copyright (c) 2015年. All rights reserved. 6 // 形状类 7 8 #import "Shape.h" 9 10 @implementation Shape 11 -(void)draw 12 { 13 NSLog(@"drawing a Shape!"); 14 } 15 -(void) Area{} 16 -(void) Length{} 17 -(void) Volum{} 18 @end
//Point类 .h和.m文件
1 // Point.h 2 // 继承 3 // 4 // Created by ma c on 15/8/11. 5 // Copyright (c) 2015年. All rights reserved. 6 // 点类 7 8 #import "Shape.h" 9 10 @interface MyPoint : Shape 11 @property(nonatomic,assign) CGFloat x; 12 @property(nonatomic,assign) CGFloat y; 13 -(id)initWithX:(CGFloat)m andY:(CGFloat)n; 14 -(void)show; 15 @end
1 // Point.m 2 // 继承 3 // 4 // Created by ma c on 15/8/11. 5 // Copyright (c) 2015年. All rights reserved. 6 // 点类 7 8 #import "MyPoint.h" 9 10 @implementation MyPoint 11 -(id)initWithX:(CGFloat)m andY:(CGFloat)n 12 { 13 self = [super init]; 14 if(self) 15 { 16 _x = m; 17 _y = n; 18 } 19 return self; 20 } 21 -(void)draw 22 { 23 NSLog(@"drawing a point!"); 24 } 25 -(void)show 26 { 27 NSLog(@"x:%.1f,y:%.1f",_x,_y); 28 } 29 @end
//圆类Circle .h和.m文件
1 // Circle.h 2 // 继承 3 // 4 // Created by ma c on 15/8/12. 5 // Copyright (c) 2015年. All rights reserved. 6 // 圆类 7 8 #import "MyPoint.h" 9 10 @interface Circle : MyPoint 11 @property(nonatomic,assign)CGFloat radius; 12 -(id)initWithX:(CGFloat)m andY:(CGFloat)n andRadius:(CGFloat)r; 13 @end
1 // Circle.m 2 // 继承 3 // 4 // Created by ma c on 15/8/12. 5 // Copyright (c) 2015年. All rights reserved. 6 // 圆类 7 8 #import "Circle.h" 9 #define PI 3.14 10 @implementation Circle 11 -(id)initWithX:(CGFloat)m andY:(CGFloat)n andRadius:(CGFloat)r 12 { 13 self = [super init]; 14 if(self) 15 { 16 super.x = m; 17 super.y = n; 18 _radius = r; 19 } 20 return self; 21 } 22 -(void) Area 23 { 24 super.area = PI*_radius*_radius; 25 } 26 -(void) Length 27 { 28 super.length = 2*PI*_radius; 29 } 30 -(void)draw 31 { 32 NSLog(@"drawing a circle!"); 33 } 34 -(void)show 35 { 36 [super show]; 37 NSLog(@"radius:%.1f,area:%.1f,Length:%.1f",_radius,super.area,super.length); 38 } 39 @end
//球体类Sphere .h和.m文件
1 // Sphere.h 2 // 继承 3 // 4 // Created by ma c on 15/8/12. 5 // Copyright (c) 2015年. All rights reserved. 6 // 球体类 7 8 #import "Circle.h" 9 10 @interface Sphere : Circle 11 @property(nonatomic,assign)CGFloat z; 12 -(id)initWithX:(CGFloat)m andY:(CGFloat)n andZ:(CGFloat)t andRadius:(CGFloat)r; 13 @end
1 // Sphere.m 2 // 继承 3 // 4 // Created by ma c on 15/8/12. 5 // Copyright (c) 2015年. All rights reserved. 6 // 球体类 7 8 #import "Sphere.h" 9 #define PI 3.14 10 @implementation Sphere 11 @synthesize z; 12 -(id)initWithX:(CGFloat)m andY:(CGFloat)n andZ:(CGFloat)t andRadius:(CGFloat)r 13 { 14 if(self = [super init]) 15 { 16 super.x = m; 17 super.y = n; 18 z = t; 19 super.radius = r; 20 } 21 return self; 22 } 23 -(void)draw 24 { 25 NSLog(@"draw a sphere!"); 26 } 27 -(void) Area 28 { 29 super.area = 4*PI*super.radius*super.radius; 30 } 31 -(void) Volum 32 { 33 super.volum = 4/3*PI*super.radius*super.radius*super.radius; 34 } 35 -(void)show 36 { 37 NSLog(@"x:%.1f,y:%.1f,z:%.1f",super.x,super.y,z); 38 NSLog(@"radius:%.1f,area:%.1f,volum:%.1f",super.radius,super.area,super.volum); 39 } 40 @end
//矩形类Rectangle .h和.m文件
1 // Rectangle.h 2 // 继承 3 // 4 // Created by ma c on 15/8/11. 5 // Copyright (c) 2015年. All rights reserved. 6 // 矩形类 7 8 #import "MyPoint.h" 9 10 @interface Rectangle : MyPoint 11 12 @property(nonatomic,assign) CGFloat len; 13 @property(nonatomic,assign) CGFloat hei; 14 -(id)initWith:(CGFloat)m andY:(CGFloat)n andLen:(CGFloat) l andHei:(CGFloat)h; 15 @end
1 // Rectangle.m 2 // 继承 3 // 4 // Created by ma c on 15/8/11. 5 // Copyright (c) 2015年. All rights reserved. 6 // 矩形类 7 8 #import "Rectangle.h" 9 10 @implementation Rectangle 11 -(id)initWith:(CGFloat)m andY:(CGFloat)n andLen:(CGFloat) l andHei:(CGFloat)h 12 { 13 self = [super init]; 14 if(self) 15 { 16 self.x = m; 17 self.y = n; 18 _len = l; 19 _hei = h; 20 } 21 return self; 22 } 23 -(void) Area 24 { 25 super.area = _len*_hei; 26 } 27 -(void) Length 28 { 29 super.length = 2*(_len+_hei); 30 } 31 -(void)draw 32 { 33 NSLog(@"drawing a Rectangle!"); 34 } 35 -(void)show 36 { 37 [super show]; 38 NSLog(@"len:%.1f,hei:%.1f,area:%.1f,length:%.1f",_len,_hei,super.area,super.length); 39 } 40 @end
//正方形类Square .h和.m文件
1 // Square.h 2 // 继承 3 // 4 // Created by ma c on 15/8/11. 5 // Copyright (c) 2015年. All rights reserved. 6 // 正方形类 7 8 #import "Rectangle.h" 9 10 @interface Square : Rectangle 11 @end
1 // Square.m 2 // 继承 3 // 4 // Created by ma c on 15/8/11. 5 // Copyright (c) 2015年. All rights reserved. 6 // 正方形类 7 8 #import "Square.h" 9 10 @implementation Square 11 -(void) Area 12 { 13 self.area = super.len*super.hei; 14 } 15 -(void) Length 16 { 17 self.length = 4*self.len; 18 } 19 -(void)draw 20 { 21 NSLog(@"drawing a Square!"); 22 } 23 -(void)show 24 { 25 [super show]; 26 } 27 @end
//主函数测试
1 // main.m 2 // 继承 3 // 4 // Created by ma c on 15/8/11. 5 // Copyright (c) 2015年. All rights reserved. 6 // 7 8 #import <Foundation/Foundation.h> 9 #import "Shape.h" 10 #import "Square.h" 11 #import "MyPoint.h" 12 #import "Rectangle.h" 13 #import "Circle.h" 14 #import "Sphere.h" 15 int main(int argc, const char * argv[]) 16 { 17 @autoreleasepool 18 { 19 Shape *shape = [[Shape alloc]init]; 20 [shape draw]; 21 printf(" "); 22 23 24 MyPoint *mypoint = [[MyPoint alloc]initWithX:0.0 andY:0.0]; 25 [mypoint draw]; 26 [mypoint show]; 27 printf(" "); 28 29 30 Circle *circle = [[Circle alloc]initWithX:1.1 andY:1.1 31 andRadius:5.0]; 32 [circle Area]; 33 [circle Length]; 34 [circle draw]; 35 [circle show]; 36 printf(" "); 37 38 39 Rectangle *rectangle = [[Rectangle alloc]initWith:2.2 andY:2.2 andLen:3 andHei:8]; 40 [rectangle Area]; 41 [rectangle Length]; 42 [rectangle draw]; 43 [rectangle show]; 44 printf(" "); 45 46 47 Square *square = [[Square alloc]initWith:3.3 andY:3.3 andLen:4 andHei:4]; 48 [square Area]; 49 [square Length]; 50 [square draw]; 51 [square show]; 52 printf(" "); 53 54 Sphere *sphere = [[Sphere alloc]initWithX:4.4 andY:4.4 andZ:4.4 andRadius:6.0]; 55 [sphere Area]; 56 [sphere Volum]; 57 [sphere draw]; 58 [sphere show]; 59 printf(" "); 60 } 61 return 0; 62 }
//运行结果
2015-08-12 18:44:15.931 继承[1875:121866] drawing a Shape! 2015-08-12 18:44:15.933 继承[1875:121866] drawing a point! 2015-08-12 18:44:15.933 继承[1875:121866] x:0.0,y:0.0 2015-08-12 18:44:15.933 继承[1875:121866] drawing a circle! 2015-08-12 18:44:15.933 继承[1875:121866] x:1.1,y:1.1 2015-08-12 18:44:15.933 继承[1875:121866] radius:5.0,area:78.5,Length:31.4 2015-08-12 18:44:15.934 继承[1875:121866] drawing a Rectangle! 2015-08-12 18:44:15.934 继承[1875:121866] x:2.2,y:2.2 2015-08-12 18:44:15.934 继承[1875:121866] len:3.0,hei:8.0,area:24.0,length:22.0 2015-08-12 18:44:15.934 继承[1875:121866] drawing a Square! 2015-08-12 18:44:15.934 继承[1875:121866] x:3.3,y:3.3 2015-08-12 18:44:15.934 继承[1875:121866] len:4.0,hei:4.0,area:16.0,length:16.0 2015-08-12 18:44:15.935 继承[1875:121866] draw a sphere! 2015-08-12 18:44:15.935 继承[1875:121866] x:4.4,y:4.4,z:4.4 2015-08-12 18:44:15.935 继承[1875:121866] radius:6.0,area:452.2,volum:678.2 Program ended with exit code: 0
注释：继承Shape的形状基本都具有自己的坐标及其对应的属性(如半径、长、高、宽、面积、周长、体积等)。当然，视情况去定义。