联合和枚举的作用是什么? 我在看《C++精髓》时,觉得联合和枚举的说明不够明确,我一直看不懂因为我不知道它们是干吗的。确实是很菜的问题,但请帮帮我。 解决方案 » 免费领取超大流量手机卡,每月29元包185G流量+100分钟通话, 中国电信官方发货 联合,就是共享内存,class cell{ public: union { char c[10]; int i; int j; }; };定义一个cell a.如果a.i=10 那么:a.j=10,a.c[0]=10,....枚举enum Days // Declare enum type Days{ saturday, // saturday = 0 by default sunday = 0, // sunday = 0 as well monday, // monday = 1 tuesday, // tuesday = 2 wednesday, // etc. thursday, friday} today; // Variable today has type Days相当于:#define saturday 0#define sunday 0#define monday 1........#define friday 5 enum Days // Declare enum type Days{ saturday, // saturday = 0 by default sunday = 0, // sunday = 0 as well monday, // monday = 1 tuesday, // tuesday = 2 wednesday, // etc. thursday, friday} today; // Variable today has type Days相当于:#define saturday 0#define sunday 0#define monday 1....#define friday 5联合就是内存共享class cell{ public: union { char c[10]; int i; int j; }; };cell a;如果a.i=10,那么:a.j=10,a.c[0]=10,a.c[1]=0,a.c[2]=0,a.c[3]=0;如果a.i=256,那么:a.j=256,a.c[0]=0,a.c[1]=1,a.c[2]=0,a.c[3]=0; 数据库更新多项方法? 为何程序崩溃不生成Minidump 怎样获得非模态对话框的句柄 问一个滚动条控件的问题 原始套接字的FD_CLOSE消息问题 请问 怎么改变Tab控件的背景色, 使用SkinMagic进行了换肤,但发现字体太小,不知道是否能更改字体? 如何使vc编的控制台程序运行时不一闪而过。 如何像windows桌面一样 ,能让图标一点一点移动,也就是让它拖动到指定位置!急!!! 奇怪的问题,谁能说清楚? 如何才能设置对话框字体 关于DLL的引用,高分!
class cell{
public:
union
{
char c[10];
int i;
int j;
};
};定义一个cell a.
如果a.i=10 那么:a.j=10,a.c[0]=10,
....
枚举
enum Days // Declare enum type Days
{
saturday, // saturday = 0 by default
sunday = 0, // sunday = 0 as well
monday, // monday = 1
tuesday, // tuesday = 2
wednesday, // etc.
thursday,
friday
} today; // Variable today has type Days相当于:
#define saturday 0
#define sunday 0
#define monday 1
........
#define friday 5
{
saturday, // saturday = 0 by default
sunday = 0, // sunday = 0 as well
monday, // monday = 1
tuesday, // tuesday = 2
wednesday, // etc.
thursday,
friday
} today; // Variable today has type Days相当于:
#define saturday 0
#define sunday 0
#define monday 1
....
#define friday 5联合就是内存共享
class cell{
public:
union
{
char c[10];
int i;
int j;
};
};
cell a;
如果a.i=10,那么:a.j=10,a.c[0]=10,a.c[1]=0,a.c[2]=0,a.c[3]=0;
如果a.i=256,那么:a.j=256,a.c[0]=0,a.c[1]=1,a.c[2]=0,a.c[3]=0;