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
  
 

文章来源: chenyu.blog.csdn.net，作者：chen.yu，版权归原作者所有，如需转载，请联系作者。

原文链接：chenyu.blog.csdn.net/article/details/80954163