C语言-15-枚举

#include 

int main()
{
	enum week{mon=1,tues,wed,thurs,fri,sat,sun}day;
	printf("n请输入对应的星期:n");
	scanf_s("%d", &day);
	switch (day)
	{
	case mon:
		printf("nmonday.nn");
		break;

	case tues:
		printf("ntuesday.nn");
		break;

	case wed:
		printf("nwendsday.nn");
		break;

	case thurs:
		printf("nthursday.nn");
		break;

	case fri:
		printf("nfriday.nn");
		break;

	case sat:
		printf("nsaturday.nn");
		break;

	case sun:
		printf("nsunurday.nn");
		break;
	default:
		printf("n你输入数字错误，不在指定的范围内?nn");
	}
	return 0;
}

#include 

struct sdata //结构体类型
{
	int i;
	char c;
	double d;
};

union udata //共用体类型
{
	int i;
	char c;
	double d;
};

int main()
{
	struct sdata s;//结构体变量
	union udata u;//联合体变量
	printf("s=%dnn", sizeof(s));//输出s=16
	printf("u=%dnn", sizeof(u));//输出u=8


	return 0;
}

#include 

union udata 
{
	int i;
	char c;
	double d;
};

int main()
{
	
	union udata u;//联合体变量
	
	u.i = 10;
	printf("%d,%c,%.2lfn", u.i, u.c, u.d);
	u.c = 'A';
	printf("%d,%c,%.2lfn", u.i, u.c, u.d);
	u.d = 67.33;
	printf("%d,%c,%.2lfn", u.i, u.c, u.d);

	printf("i=%pnn", &u.i);
	printf("c=%pnn", &u.c);//三者地址一样
	printf("d=%pnn", &u.d);
	return 0;
}

#include 

int main()
{
	int x = 5, y = 9, z = 0;
	printf("x=%d,y=%d,z=%dnn", x, y, z);

	z = x & y;
	printf("x=%d,y=%d,z=%dnn", x, y, z);//输出z=1

	int k = 10;
	printf("k<<1=%dnn", k << 1);//输出k<<1=20
	printf("k>>1=%dnn", k >> 1);//输出k>>1=50
	return 0;
}