Objective-C:继承的体现

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

//  Shape.h
//  继承
//
//  Created by ma c on 15/8/11.
//  Copyright (c) 2015年. All rights reserved.
//  形状类

#import <Foundation/Foundation.h>

@interface Shape : NSObject
@property(nonatomic,assign)CGFloat length;
@property(nonatomic,assign)CGFloat area;
@property(nonatomic,assign)CGFloat volum;
-(void)draw;
-(void) Area;
-(void) Length;
-(void) Volum;
@end

//  Shape.m
//  继承
//
//  Created by ma c on 15/8/11.
//  Copyright (c) 2015年. All rights reserved.
//  形状类

#import "Shape.h"

@implementation Shape
-(void)draw
{
NSLog(@"drawing a Shape!");
}
-(void) Area{}
-(void) Length{}
-(void) Volum{}
@end

//Point类 .h和.m文件

//  Point.h
//  继承
//
//  Created by ma c on 15/8/11.
//  Copyright (c) 2015年. All rights reserved.
//  点类

#import "Shape.h"

@interface MyPoint : Shape
@property(nonatomic,assign) CGFloat x;
@property(nonatomic,assign) CGFloat y;
-(id)initWithX:(CGFloat)m andY:(CGFloat)n;
-(void)show;
@end

//  Point.m
//  继承
//
//  Created by ma c on 15/8/11.
//  Copyright (c) 2015年. All rights reserved.
//  点类

#import "MyPoint.h"

@implementation MyPoint
-(id)initWithX:(CGFloat)m andY:(CGFloat)n
{
self = [super init];
if(self)
{
_x = m;
_y = n;
}
return self;
}
-(void)draw
{
NSLog(@"drawing a point!");
}
-(void)show
{
NSLog(@"x:%.1f,y:%.1f",_x,_y);
}
@end

//圆类Circle .h和.m文件

//  Circle.h
//  继承
//
//  Created by ma c on 15/8/12.
//  Copyright (c) 2015年. All rights reserved.
//  圆类

#import "MyPoint.h"

@interface Circle : MyPoint
@property(nonatomic,assign)CGFloat radius;
-(id)initWithX:(CGFloat)m andY:(CGFloat)n andRadius:(CGFloat)r;
@end

//  Circle.m
//  继承
//
//  Created by ma c on 15/8/12.
//  Copyright (c) 2015年. All rights reserved.
//  圆类

#import "Circle.h"
#define PI 3.14
@implementation Circle
-(id)initWithX:(CGFloat)m andY:(CGFloat)n andRadius:(CGFloat)r
{
self = [super init];
if(self)
{
super.x = m;
super.y = n;
_radius = r;
}
return self;
}
-(void) Area
{
super.area = PI*_radius*_radius;
}
-(void) Length
{
super.length = 2*PI*_radius;
}
-(void)draw
{
NSLog(@"drawing a circle!");
}
-(void)show
{
[super show];
NSLog(@"radius:%.1f,area:%.1f,Length:%.1f",_radius,super.area,super.length);
}
@end

//球体类Sphere .h和.m文件

//  Sphere.h
//  继承
//
//  Created by ma c on 15/8/12.
//  Copyright (c) 2015年. All rights reserved.
//  球体类

#import "Circle.h"

@interface Sphere : Circle
@property(nonatomic,assign)CGFloat z;
-(id)initWithX:(CGFloat)m andY:(CGFloat)n andZ:(CGFloat)t andRadius:(CGFloat)r;
@end

//  Sphere.m
//  继承
//
//  Created by ma c on 15/8/12.
//  Copyright (c) 2015年. All rights reserved.
//  球体类

#import "Sphere.h"
#define PI 3.14
@implementation Sphere
@synthesize z;
-(id)initWithX:(CGFloat)m andY:(CGFloat)n andZ:(CGFloat)t andRadius:(CGFloat)r
{
if(self = [super init])
{
super.x = m;
super.y = n;
z = t;
super.radius = r;
}
return self;
}
-(void)draw
{
NSLog(@"draw a sphere!");
}
-(void) Area
{
super.area = 4*PI*super.radius*super.radius;
}
-(void) Volum
{
super.volum = 4/3*PI*super.radius*super.radius*super.radius;
}
-(void)show
{
NSLog(@"x:%.1f,y:%.1f,z:%.1f",super.x,super.y,z);
NSLog(@"radius:%.1f,area:%.1f,volum:%.1f",super.radius,super.area,super.volum);
}
@end

//矩形类Rectangle .h和.m文件

//  Rectangle.h
//  继承
//
//  Created by ma c on 15/8/11.
//  Copyright (c) 2015年. All rights reserved.
//  矩形类

#import "MyPoint.h"

@interface Rectangle : MyPoint

@property(nonatomic,assign) CGFloat len;
@property(nonatomic,assign) CGFloat hei;
-(id)initWith:(CGFloat)m andY:(CGFloat)n andLen:(CGFloat) l andHei:(CGFloat)h;
@end

//  Rectangle.m
//  继承
//
//  Created by ma c on 15/8/11.
//  Copyright (c) 2015年. All rights reserved.
//  矩形类

#import "Rectangle.h"

@implementation Rectangle
-(id)initWith:(CGFloat)m andY:(CGFloat)n andLen:(CGFloat) l andHei:(CGFloat)h
{
self = [super init];
if(self)
{
self.x = m;
self.y = n;
_len = l;
_hei = h;
}
return self;
}
-(void) Area
{
super.area = _len*_hei;
}
-(void) Length
{
super.length = 2*(_len+_hei);
}
-(void)draw
{
NSLog(@"drawing a Rectangle!");
}
-(void)show
{
[super show];
NSLog(@"len:%.1f,hei:%.1f,area:%.1f,length:%.1f",_len,_hei,super.area,super.length);
}
@end

//正方形类Square .h和.m文件

//  Square.h
//  继承
//
//  Created by ma c on 15/8/11.
//  Copyright (c) 2015年. All rights reserved.
//  正方形类

#import "Rectangle.h"

@interface Square : Rectangle
@end

//  Square.m
//  继承
//
//  Created by ma c on 15/8/11.
//  Copyright (c) 2015年. All rights reserved.
//  正方形类

#import "Square.h"

@implementation Square
-(void) Area
{
self.area = super.len*super.hei;
}
-(void) Length
{
self.length = 4*self.len;
}
-(void)draw
{
NSLog(@"drawing a Square!");
}
-(void)show
{
[super show];
}
@end

//主函数测试

//  main.m
//  继承
//
//  Created by ma c on 15/8/11.
//  Copyright (c) 2015年. All rights reserved.
//

#import <Foundation/Foundation.h>
#import "Shape.h"
#import "Square.h"
#import "MyPoint.h"
#import "Rectangle.h"
#import "Circle.h"
#import "Sphere.h"
int main(int argc, const char * argv[])
{
@autoreleasepool
{
Shape *shape = [[Shape alloc]init];
[shape draw];
printf("\n");

MyPoint *mypoint = [[MyPoint alloc]initWithX:0.0 andY:0.0];
[mypoint draw];
[mypoint show];
printf("\n");

Circle *circle = [[Circle alloc]initWithX:1.1 andY:1.1
andRadius:5.0];
[circle Area];
[circle Length];
[circle draw];
[circle show];
printf("\n");

Rectangle *rectangle = [[Rectangle alloc]initWith:2.2 andY:2.2 andLen:3 andHei:8];
[rectangle Area];
[rectangle Length];
[rectangle draw];
[rectangle show];
printf("\n");

Square *square = [[Square alloc]initWith:3.3 andY:3.3 andLen:4 andHei:4];
[square Area];
[square Length];
[square draw];
[square show];
printf("\n");

Sphere *sphere = [[Sphere alloc]initWithX:4.4 andY:4.4 andZ:4.4 andRadius:6.0];
[sphere Area];
[sphere Volum];
[sphere draw];
[sphere show];
printf("\n");
}
return 0;
}

//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。