Simple encapsulation of inherited polymorphism

First create a project, then create an animal Class (Animal), then create a cat class and a dog class, and finally create a human to feed the animals.

Animal Inheritance NSObject

And cats and dogs inherit animal classes.

Human feeding also inherits NSObject

Animal class

//Declaration of Class#import<Cocoa/Cocoa.h>@interfaceAnimal:nsobject-(void) Jiao;-(void) eat;@end//Realization of Class#import "Animal.h"@implementationAnimal-(void) jiao{NSLog (@"called");}-(void) eat{NSLog (@"Eat");}@end

Cat class

#import "Animal.h"@interfaceCat:animal-(void) Jiao;@end#import "Cat.h"@implementationCat-(void) jiao{NSLog (@"Meow Meow");}-(void) eat{NSLog (@"The cat eats the fish");}@end

Human feeding

#import <Foundation/Foundation.h>#import"Animal.h"@ Interface  weishi:nsobject-(void) Feed: (Animal *) Animal; @end #import " Weishi.h " @implementation Weishi-(void) Feed: (Animal *) animal{    [Animal eat];} @end

Finally instantiate the object in the main function

#import<Foundation/Foundation.h>#import "Animal.h"#import "Cat.h"#import "Dog.h"#import "Weishi.h"intMainintargcConst Char*argv[]) {@autoreleasepool {IDtest=[[Animal alloc]init];                [Test jiao]; Animal*test1=[[Cat alloc]init];                [Test1 Jiao]; IDTest2=[[Dog alloc]init];                [Test2 eat]; IDtest3=[[Weishi alloc]init];        [Test3 Feed:test2]; }    return 0;}

Finally get the following.

Of course, this is basically the simplest.

Simple encapsulation of inherited polymorphism