[nature of class (in Objective-C language)]

Preface

stay Objective-C In language , What is the nature of class ？

One 、 What are the five areas of memory ？

1. Stack —— Store local variables
2. Pile up —— For storage programmers malloc,realloc,calloc The space you applied for , And class objects .
3.BSS paragraph —— Store uninitialized global variables , Static variables
4. Data segment （ The constant area ）—— Store initialized global variables , Static variables .
5. Code segment —— Binary code of storage class , Method binary code

Two 、 The essence of class

1. When is the class loaded into the code segment ？

When the class is first accessed , Is loaded into the code segment , be called “ Class loading ”.

2. Once the class is loaded into the code segment , When to recycle ？

Recycle at the end of the program .

3. In what form are classes stored in code segments ？

1） Preface ： Any data stored in memory , There's a data type .
2） Preface ： Any space requested in memory , There are also their own types .
3） What kind of space is there to store classes in code snippets ：Class Type of
4） Steps to store classes in code snippets ：
a. Now create a Class object .
b. Class yes Foundation A class in the framework , that Class What is the object , Is used to store classes .
c. Store the class information in this Class Among objects
d. This Class An object should have at least three properties ：

• ClassName Storage class name
• Storage class properties
• Methods of storing classes
  e. remember , This is an object , So there's one in it iSA The pointer , This pointer points to the parent class of this class .

summary

This article describes the nature of classes , Then we will add how to get this class object , And how to call class methods through class objects .