Objective-c polymorphism

In object-oriented languages, many different implementations of interfaces are polymorphic. Polymorphism responds to different objects in response to the same method, polymorphism in code, that is, a variety of forms, must have inheritance, no inheritance there is no polymorphism in the use of polymorphism, will be dynamic detection, to invoke the real object method

//
// main.m
// mobile

#import <Foundation / Foundation.h>
#import "Communication.h"
#import "Electrograph.h"
#import "Telephone.h"
#import "Student.h"
int main (int argc, const char * argv []) {
    @autoreleasepool {
        Peerson * p = [[Student alloc] init];
      Communication * cuo = [[Electrograph alloc] init];
        [p sayhi: cuo];
        cuo = [[Communication alloc] init];
        [p sayhi: cuo];
        cuo = [[Telephone alloc] init];
        [p sayhi: cuo];
    }
    return 0;
}
 

//
// Peerson.h
// mobile
#import <Foundation / Foundation.h>
#import "Communication.h"
@interface Peerson: NSObject
-(void) sayhi: (Communication *) say;
@end
//
// Peerson.m
// mobile

#import "Peerson.h"

@implementation Peerson
-(void) sayhi: (Communication *) say {
    [say call];
}
@end
//
// Student.h
// mobile
#import "Peerson.h"

@interface Student: Peerson

@end

//
// Student.h
// mobile


#import "Peerson.h"

@interface Student: Peerson

@end
//
// Communication.h
// mobile

#import <Foundation / Foundation.h>

@interface Communication: NSObject
-(void) call;
@end

//
// Communication.m
// mobile

#import "Communication.h"

@implementation Communication
-(void) call {
    NSLog (@ "I'm calling now");
}
@end
//
// Electrograph.h
// mobile

#import "Communication.h"

@interface Electrograph: Communication

@end

//
// Electrograph.m
// mobile
#import "Electrograph.h"

@implementation Electrograph
-(void) call {
    NSLog (@ "I'm calling with my family");
}
@end
//
// Telephone.h
// mobile
#import "Communication.h"

@interface Telephone: Communication

@end

//
// Telephone.m
// mobile

#import "Telephone.h"

@implementation Telephone
-(void) call {
    NSLog (@ "My mobile phone can access the Internet");
}
@end

Objective-c polymorphism