[Objective-c 基础 - 2.1] 封装

A.封装内部细节，根据需求暴露方法

 #import <Foundation/Foundation.h>

 @interface Student : NSObject
 {
     int age;
 }

 - (void) setAge:(int) newAge;
 - (int) age;

 - (void) study;

 @end

 @implementation Student

 - (void) setAge:(int) newAge
 {
     if (newAge <= )
     {
         age = ;
     }
     else
     {
         age = newAge;
     }
 }

 - (int) age
 {
     return age;
 }

 - (void) study
 {
     NSLog(@"%d岁的学生在学习", age);
 }

 @end

 int main()
 {
     Student *stu = [Student new];
     [stu setAge:];
     [stu study];

     NSLog(@"这个学生的年龄是%d", [stu age]);

     return ;
 }

 

B.封装规范

使用下划线开头命名成员变量

 @interface Student : NSObject
 {
     int _no;
     Sex _sex;
 }

 - (Sex) sex;
 - (void) setSex:(Sex) newSex;
 - (int) no;
 - (void) setNo:(int) no;

 @end