Objective-C program structure

Class is the core of objective-C, and objective-CProgramAll are performed around classes. The objective-C program consists of at least three parts:

1. Class interface: defines the class data and methods, but does not include the implementation of methods.Code.

2. Class implementation: code for implementing class methods is stored.

3. Applications: applications that call classes to complete some actual operations.

Class interface, which can be understood as the header file *. h In the C/C ++ language, that is, the definition of the class.

Class implementation, we can understand it as the *. cpp file in the C ++ language, that is, the class implementation code.

The application is also an application composed of the main function and other function code that implements some functions.