[Objective-c 基础

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 <= 0)
    {
        age = 1;
    }
    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:21];
    [stu study];
   
    NSLog(@"这个学生的年龄是%d", [stu age]);
   
    return 0;
}

 

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