IOS学习笔记十(多态)

1、多态

相同类型调用同一个方法呈现多种不同的行为特征就是多态

当子类对象直接赋值给父类指针变量，父类 *p = [子类 new];，运行类型是子类，编译类型是父类，所以p不能调用子类单独实现的方法，如果子类重写了父类方法，p调用的方法会是子类重写的方法

 

 

 

isKindOfClass:clazz

判断该对象是否为clazz或者其子类的实例

 

 

 

 

 

 

2、测试demo

KFBase.h

#import <Foundation/Foundation.h> #ifndef KFBase_h #define KFBase_h @interface KFBase : NSObject -(void)base; -(void)test; @end #endif /* KFBase_h */

 

 

 

KFBase.m

#import <Foundation/Foundation.h> #import "KFBase.h" @implementation KFBase -(void)base { NSLog(@"parent base method"); } -(void)test { NSLog(@"parent test method"); } @end

 

 

 

SubClass.h

#import "KFBase.h" #ifndef Subclass_h #define Subclass_h @interface Subclass : KFBase -(void)sub; -(void)test; @end #endif /* Subclass_h */

 

 

 

SubClass.m

#import <Foundation/Foundation.h> #import "Subclass.h" @implementation Subclass -(void)sub { NSLog(@"child sub method"); } -(void)test { NSLog(@"chile test method"); } @end

 

 

 

main.m

#import "KFBase.h" #import "Subclass.h" int main(int argc, char * argv[]) { @autoreleasepool { KFBase *base = [KFBase new]; [base base]; [base test]; Subclass *sub = [Subclass new]; [sub base]; [sub test]; [sub sub]; KFBase *seBase = [Subclass new]; [seBase base]; [seBase test]; //下面运行会编译出错 // [seBase sub]; id dy = seBase; [dy sub]; NSLog(@"sub是KFBase的子类吗？%d",[sub isKindOfClass:[KFBase class]]); } }

 

 

 

 

 

 

 

3、运行结果

parent base method parent test method parent base method chile test method child sub method parent base method chile test method child sub method sub是KFBase的子类吗？1

 

 

 

 

 

 

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