(Ios development study note 7) Composition of objective C basic classes

Frontier:

A Brief Introduction to the composition of Objective C classes includes the methods of attributes, variables, methods, and multiple parameters.

 

Step One select and create a class

Step Two create an H file

Notes:

 1 + and-

+ Static method (class method)-object method (called only after an instance is required)

 2The variables in interface {} are private variables of the class, and the External table cannot be called.

3 @ property indicates the property

Description of common parameters

Nonatomic: Non-atomic, thread unsafe

Atomic: atomic

Readwrite: read/write

Readonly: Read-Only

Copy is used to create and allocate a new space and copy the content from the original address.

Assign is just a simple pointer transfer.

Retain is after passing the pointer retainCount + 1

 

4 multi-parameter method implementation

The multi-parameter method implementation in other languages is generally the void method name (Data Format parameter 1, data format parameter 2 );

Multi-parameter methods in objective C are implemented

The advantage of this method is that it is helpful for reading

 

Step Three create m file

Note:

@ Synthesize carno = _ carno; implement attributes and create the SetCarno set method at the same time (if the set method is not implemented, attributes cannot be set)