oc11---结构体作为属性

//
//  main.m
//  结构体作为对象的属性

#import <Foundation/Foundation.h>

typedef struct {
    int year;
    int month;
    int day;
} Date;

@interface Student : NSObject
{
    @public
    NSString *_name;
    // struct Date birthday;
    Date _birthday;
}
- (void)say;
@end
@implementation Student
- (void)say
{
    NSLog(@"name = %@; year = %i, month = %i, day = %i", _name, _birthday.year, _birthday.month, _birthday.day);
}
@end

int main(int argc, const char * argv[]) {
    Student *stu = [Student new];//结构体里面的值都是0
    stu->_name = @"lnj";
    // 1.结构体只能在定义的时候初始化
    // 2.系统并不清楚它是数组还是结构体
    
    //初始化结构体属性
    //方法一:强制转换
    stu->_birthday = (Date){1986, 1, 15};//大括号有可能是数组，
    
    //方法二:定义一个新的结构体,给d赋值,将d赋值给_birthday
    Date d = {1986, 1, 15};
    stu->_birthday = d;
    
    //方法三:分别赋值
    stu->_birthday.year = 1986;
    stu->_birthday.month = 1;
    stu->_birthday.day = 15;
    
    // 3.让学生说出自己的姓名和生日
    [stu say];
    
    
    
    Date d1  = {1999, 1, 5};
    Date d2;
    d2 = d1; // 本质是将d1所有的属性的值都拷贝了一份赋值给d;不是传递地址
    
    d2.year = 2000;
    printf("d1 = year = %i
", d1.year);//1999
    printf("d2 = year = %i
", d2.year);//2000
    return 0;
}