The nature of the class

//

Main.m

06-Nature of the class

//

Created by Apple on 13-8-8.

Copyright (c) 2013 itcast. All rights reserved.

//

#import <Foundation/Foundation.h>

#import "Person.h"

#import "Student.h"

#import "GoodStudent.h"

/*

1. When the program starts, all classes and classifications in the project are loaded, and the +load method for each class and classification is called after it is loaded. will only be called once.

2. When a class is used for the first time, the +initialize method of the current class is called

3. Load the parent class first, then load the subclass (call the +load method of the parent class first, and then call the +load method of the subclass)

Initializes the parent class first, initializes the subclass (invokes the +initialize method of the parent class, and then calls the +initialize method of the subclass)

*/

int main ()

{

[[Goodstudent alloc] init];

return 0;

}

void Test1 ()

{

Person *p = [[Person alloc] init];

[Person Test];

In-Memory class objects

Class object = = Class

Class C = [P class];

[C Test];

Person *P2 = [[C new] init];

NSLog (@ "00000");

}

void Test ()

{

Use the person class to create an object of 2 person types

Person *p = [[Person alloc] init];

Person *P2 = [[Person alloc] init];

Person *P3 = [[Person alloc] init];

Get the class object in memory

Class C = [P class];

Class C2 = [P2 class];

Get the class object in memory

Class C3 = [Person class];

NSLog (@ "c=%p, c2=%p, c3=%p", C, C2, C3);

The class itself is also an object, a class-type object, or a class object

/*

Create a person class object with class

Create an object of person type with the person class object

*/

}

The nature of the class