类的合理设计

#import <Foundation/Foundation.h>

 

typedef enum {

    SexMan,

    SexWoman

} Sex;

 

typedef struct {

    int year;

    int month;

    int day;

} Date;

 

 

typedef enum {

    ColorBlack,

    ColorRed,

    ColorGreen

} Color;

 

@interface Dog : NSObject

{

    @public

    double weight; // 体重

    Color curColor; // 毛色

}

 

- (void)eat;

- (void)run;

@end

 

@implementation Dog

- (void)eat

{

    // 每吃一次，体重就加1

    weight += 1;

    //weight = weight +  1;

    NSLog(@"狗吃完这次后的体重是%f", weight);

}

 

- (void)run

{

    weight -= 1;

    NSLog(@"狗跑完这次后的体重是%f", weight);

}

@end

 

/*

学生

成员变量：性别、生日、体重、最喜欢的颜色、狗(体重、毛色，吃、跑)

方法：吃、跑步、遛狗(让狗跑)、喂狗（让狗吃）

*/

@interface Student : NSObject

{

    @public

    Sex sex; // 性别

    Date birthday; // 生日

    double weight; // 体重(kg)

    Color favColor; // 最喜欢的颜色

    char *name;

    

    // 重点：狗

    Dog *dog;

}

- (void)eat;

- (void)run;

- (void)print;

 

- (void)liuDog;

- (void)weiDog;

@end

 

@implementation Student

 

- (void)liuDog

{

    // 让狗跑起来（调用狗的run方法）

    [dog run];

}

 

- (void)weiDog

{

    // 让狗吃东西(调用狗的eat方法)

    [dog eat];

}

 

- (void)print

{

    NSLog(@"性别=%d, 喜欢的颜色=%d, 姓名=%s, 生日=%d-%d-%d", sex, favColor, name, birthday.year, birthday.month, birthday.day);

}

 

- (void)eat

{

    // 每吃一次，体重就加1

    weight += 1;

    //weight = weight +  1;

    NSLog(@"学生吃完这次后的体重是%f", weight);

}

 

- (void)run

{

    weight -= 1;

    NSLog(@"学生跑完这次后的体重是%f", weight);

}

@end

 

int main()

{

    Student *s = [Student new];

    

    Dog *d = [Dog new];

    d->curColor = ColorGreen;

    d->weight = 20;

    s->dog = d;

    

    

    [s liuDog];

    

    [s weiDog];

    return 0;

}

 

 

void test()

{

    Student *s = [Student new];

    s->weight = 50;

    

    // 性别

    s->sex = SexMan;

    

    // 生日

    Date d = {2011, 9, 10};

    s->birthday = d;

    

    s->name = "Jack";

    

    /*

     s->birthday.year = 2011;

     s->birthday.month = 9;

     s->birthday.day = 10;

     */

    

    // 喜欢的颜色

    s->favColor = ColorBlack;

    /*

     [s eat];

     [s eat];

     

     [s run];

     [s run];

     */

    

    [s print];

}