IOS Objective-C 继承(虚方法)

#import <Foundation/Foundation.h>

@interface Father : NSObject
-(void)jump;
@end

#import "Father.h"

@implementation Father
-(void)jump{
NSLog(@"Father can jump 1.8m");
return ;
}
@end

#import "Father.h"

@interface Son : Father
@end

#import "Son.h"

@implementation Son
-(void)jump{
NSLog(@"Son can jump 1.6m");
return ;
}
@end

//
//  main.m
//  继承(虚方法)
//
//  Created by X-Liang on 14-4-9.
//  Copyright (c) 2014年 X-Liang. All rights reserved.
//

#import <Foundation/Foundation.h>
#import "Father.h"
#import "Son.h"
int main(int argc, const char * argv[])
{

@autoreleasepool {
//父类的指针可以指向子类的对象
//虚方法：调用时不看指针看对象的方法为虚方法
//OC 中对象的调用都是不看指针看对象，所以OC中的方法为虚方法
//不同事物被相同事件触发，产生不同结果
Son *son=[[Son alloc] init];
Father *p=son;
//调用的是子类的jump方法，调用方法是不看指针，看对象，对象的地址调用对象的方法
//虽然是Father的指针，但是Son对象的地址
//对象的地址调用对象的方法
[p jump];
}
return 0;
}

#import <Foundation/Foundation.h>

@interface Animal : NSObject

-(void)BeBeatn;//表示被打时的响应

@end
#import "Animal.h"

@implementation Animal

-(void)BeBeatn{
return ;
}

@end
#import "Animal.h"

@interface Cat : Animal

@end
#import "Cat.h"

@implementation Cat

-(void)BeBeatn{
NSLog(@"Brak ank jump to hight");
return ;
}

@end
#import "Animal.h"

@interface Dog : Animal

@end

#import "Dog.h"

@implementation Dog

-(void)BeBeatn{
NSLog(@"Give a hard bit");
return ;
}

@end
#import "Animal.h"

@interface Forg : Animal

@end

#import "Forg.h"

@implementation Forg

-(void)BeBeatn{
NSLog(@"Do nothing");
return ;
}

@end
#import <Foundation/Foundation.h>
#import "Animal.h"
//#import "Cat.h"
//#import "Dog.h"
//#import "Forg.h"
@interface Human : NSObject
//如果没有虚方法的话，需要声明三个函数
//-(void)BeatDog:(Dog *)dog;
//-(void)BeatCat:(Cat *)cat;
//-(void)BeatForg:(Forg *)forg;
//因为父类指针可以指向子类，所以可以仅声明一个BeatAnimal方法即可，传递Animal指针
-(void)BeatAnimal:(Animal *)animal;//形参为*Animal，为父类指针，可以指向Dog，Cat，Forg对象

@end
#import "Human.h"

@implementation Human

-(void)BeatAnimal:(Animal *)animal{
NSLog(@"Beat %@",[animal class]);//输出Animal的类名
[animal BeBeatn];
return ;
}
@end

#import <Foundation/Foundation.h>
#import "Dog.h"
#import "Cat.h"
#import "Animal.h"
#import "Human.h"
#import "Forg.h"
int main(int argc, const char * argv[])
{

@autoreleasepool {

// insert code here...
// NSLog(@"Hello, World!");
Forg *forg=[[Forg alloc] init];
Dog *dog=[[Dog alloc] init];
Cat *cat=[[Cat alloc] init];
Human *xiaoming=[[Human alloc] init];
//Animal *animal=[[Animal alloc] init];
[xiaoming BeatAnimal:dog];
[xiaoming BeatAnimal:forg];
[xiaoming BeatAnimal:cat];
}
return 0;
}