程序语言-选择语言之switch case
多选一，类似if else if else if else
模版：
Switch（选择条件）
｛
Case（条件一）//相当于if
Console.Writeline(“******”);
Break;
Case(2)
Console.Writeline(“******”);
Break;
…………
…………
default：//相当于else
Console.Writeline(“******”);
Break;
输入月份日期，输出第几天
｝
Console.Write("请输入月份：");
int a = int.Parse(Console.ReadLine());
Console.Write("请输入日期：");
int d = int.Parse(Console.ReadLine());
int m1 = 31, m2 = 28, m3 = 31, m4 = 30, m5 = 31, m6 = 30, m7 = 31, m8 = 31, m9 = 30, m10 = 31, m11 = 30;
switch(a)
{
case 1:
Console.WriteLine("第"+d+"天");
break;
case 2:
Console.WriteLine("第"+(m1+d)+"天");
break;
case 3:
Console.WriteLine("第"+(m1+m2+d)+"天");
break;
case 4:
Console.WriteLine("第"+(m1+m2+m3+d)+"天");
break;
case 5:
Console.WriteLine("第"+(m1+m2+m3+m4+d)+"天");
break;
case 6:
Console.WriteLine("第"+(m1+m2+m3+m4+m5+d)+"天");
break;
case 7:
Console.WriteLine("第"+(m1+m2+m3+m4+m5+m6+d)+"天");
break;
case 8:
Console.WriteLine("第"+(m1+m2+m3+m4+m5+m6+m7+d)+"天");
break;
case 9:
Console.WriteLine("第"+(m1+m2+m3+m4+m5+m6+m7+m8+d)+"天");
break;
case 10:
Console.WriteLine("第"+(m1+m2+m3+m4+m5+m6+m7+m8+m9+d)+"天");
break;
case 11:
Console.WriteLine("第" +(m1+m2+m3+m4+m5+m6+m7+m8+m9+m10+d)+"天");
break;
case 12:
Console.WriteLine("第" +(m1+m2+m3+m4+m5+m6+m7+m8+m9+m10+m11+ d )+"天");
break;
default:
Console.WriteLine("您输入的有误！");
break;
}
Console.ReadLine();
汇总十个小题目练习：
Console.WriteLine("1.键盘键入三个数，找出来最大的数。");
Console.WriteLine("2.“现在几点了？”键盘键入小时数，判断是上午还是下午。打印出来现在是上午几点还是下午几点");
Console.WriteLine("3.输入一个小于等于100的整数，判断：?是小于10的?两位数?是100");
Console.WriteLine("4.输入学生姓名，输入考试成绩,若是100,【恭喜你***，满分通过！】若是大于等于80小于100，【**,你很优秀，继续保持！】若是大于等于60小于80，【**成绩良好】大于等于50小于60，【**就差一点点，下次一定要至少及格！】");
Console.WriteLine("5.输入年份，判断是否是闰年");
Console.WriteLine("6.有一组函数：y = x (x<1)；y = 2x -1 (1<=x<10)； y = 3x-11 (x>=10)。括号内是x的满足条件。实现功能，随意输入一个x值，输出y的值。");
Console.WriteLine("7.相亲过程：你有房子么？你有钱么？你有能力么？【结婚吧】【先买房子在结婚】【先赚钱再买房子再结婚】都没有【拜拜~~】利用if嵌套做相亲过程");
Console.WriteLine("8.输入年月日，看看格式是否正确");
Console.WriteLine("9.方程ax2+bx+c=0;一元二次方程。求根△=b2-4ac；若△<0方程无实根若△>0，方程有两个不相同的实根x1 x2若△=0，方程有两个相同的实根");
Console.WriteLine("10.标准体重：");
Console.Write("请输入题目编号：");
int a = int.Parse(Console.ReadLine());
switch (a)
{
case 1:
Console.Write("请输入数字1：");
int x = int.Parse(Console.ReadLine());
Console.Write("请输入数字2：");
int y = int.Parse(Console.ReadLine());
Console.Write("请输入数字3：");
int z = int.Parse(Console.ReadLine());
if (x < y)
{
if (y < z)
{
Console.WriteLine("最大的数字式" + z);
}
else
{
Console.WriteLine("最大的数字式" + y);
}
}
else
{
if (x > z)
{
Console.WriteLine("最大的数字式" + x);
}
else if (x < z)
{
Console.WriteLine("最大的数字式" + z);
}
else
{
Console.WriteLine("最大的数字是：" + x);
}
}
break;
case 2:
Console.Write("现在几点了？");
double t = double.Parse(Console.ReadLine());
if (t > 12 && t < 24)
{
Console.WriteLine("现在的时间是：" + (t - 12) + "pm");
}
else if (t <= 0)
{
Console.WriteLine("现在的时间是：" + t + "am");
}
else
{
Console.WriteLine("输入错误！");
}
break;
case 3:
Console.Write("请输入一位小于100的正数：");
int s = int.Parse(Console.ReadLine());
if (s < 101 && s >= 0)
{
if (s < 10)
{
Console.WriteLine("小于10！");
}
else if (s == 100)
{
Console.WriteLine("数字是100！");
}
else
{
Console.WriteLine("数字是两位数！");
}
}
else
{
Console.WriteLine("输入有误！");
}
break;
case 4:
Console.Write("请输入姓名：");
string name = Console.ReadLine();
Console.Write("请输入成绩");
double h = double.Parse(Console.ReadLine());
if (h <= 100 && h >= 0)
{
if (h == 100)
{
Console.Write("恭喜你" + name + "，满分通过！");
}
else if (h < 100 && h <= 80)
{
Console.Write("" + name + ",你很优秀，继续保持！");
}
else if (h < 80 && h >= 60)
{
Console.Write("" + name + ",成绩良好");
}
else if (h >= 50 && h < 60)
{
Console.Write("" + name + ",就差一点点，下次一定要至少及格！");
}
else
{
Console.Write("" + name + "笨蛋！");
}
}
else
{
Console.WriteLine("输入有误！");
}
break;
case 5:
Console.Write("请输入年份：");
int n = int.Parse(Console.ReadLine());
if (n <= 9999 && n >= 0)
{
if ((n % 4 == 0 && n % 10 != 0) || n % 400 == 0)
{
Console.Write("是闰年");
}
else
{
Console.Write("不是闰年");
}
}
else
{
Console.WriteLine("输入有误！");
}
break;
case 6:
Console.Write("请输入一个x的值");
int xx = int.Parse(Console.ReadLine());
if (xx >= 10)
{
int yy = 3 * xx - 11;
Console.WriteLine("y的数值是" + yy);
}
else
{
if (xx < 1)
{
Console.WriteLine("y的数值是" + xx);
}
else
{
int yy = 2 * xx - 1;
Console.WriteLine("y的数值是" + yy);
}
}
break;
case 7:
Console.Write("你有房子么？");
string c = Console.ReadLine();
if (c == "有")
{
Console.WriteLine("结婚吧");
}
else
{
Console.Write("你有钱么？");
string d = Console.ReadLine();
if (d == "有")
{
Console.WriteLine("先买房子在结婚？");
}
else
{
Console.Write("你有能力么？");
string e = Console.ReadLine();
if (e == "有")
{
Console.WriteLine("先挣钱再买房子在结婚？");
}
else
{
Console.WriteLine("拜拜！");
}
}
}
break;
case 8:
Console.Write("请输入年份：");
int ye = int.Parse(Console.ReadLine());
Console.Write("请输入月份：");
int mo = int.Parse(Console.ReadLine());
Console.Write("请输入日：");
int da = int.Parse(Console.ReadLine());
if (ye <= 9999 && ye >= 0)
{
if (mo <= 12 && mo >= 1)
{
if (da <= 31 && da >= 0)
{
if (mo == 1 || mo == 3 || mo == 5 || mo == 7 || mo == 8 || mo == 10 || mo == 12)
{
Console.WriteLine("您输入的日期是：" + ye + mo + da);
}
else if ((mo == 4 || mo == 6 || mo == 9 || mo == 11) && ye < 31)
{
Console.WriteLine("您输入的日期是：" + ye + mo + da);
}
else if ((ye % 4 == 0 && ye % 10 != 0) || ye % 400 == 0 && da <= 29)
{
Console.WriteLine("您输入的日期是：" + ye + mo + da);
}
else if ((ye % 4 != 0 && ye % 10 == 0) || ye % 400 != 0 && da < 29)
{
Console.WriteLine("您输入的日期是：" + ye + mo + da);
}
else
{
Console.WriteLine("输入错误！");
}
}
else
{
Console.WriteLine("输入错误！");
}
}
else
{
Console.WriteLine("输入错误！");
}
}
else
{
Console.WriteLine("输入错误！");
}
break;
case 9:
Console.WriteLine("求方乘ax*x+bx+c=0的解");
Console.Write("请输入a:");
double qq = double.Parse(Console.ReadLine());
Console.Write("请输入b:");
double ww = double.Parse(Console.ReadLine());
Console.Write("请输入c:");
double ee = double.Parse(Console.ReadLine());
double de = ww * ww - 4 * qq * ee;
if (de < 0)
{
Console.WriteLine("方乘无解");
}
else
{
if (de == 0)
{
double x1 = (-ww + Math.Sqrt(de)) / (2 * a);
Console.WriteLine("方乘有一个解，x1=x2=" + x1);
}
else
{
double x1 = (-ww + Math.Sqrt(de)) / (2 * a);
double x2 = (-ww - Math.Sqrt(de)) / (2 * a);
Console.WriteLine("方乘有2个解，x1=" + x1, "x2=" + x2);
}
}
break;
case 10:
Console.Write("请输入性别：");
string sex = Console.ReadLine();
Console.Write("请输入身高");
double hi = double.Parse(Console.ReadLine());
Console.Write("请输入体重");
double w = double.Parse(Console.ReadLine());
double k1 = w - hi + 100;
double k2 = w - hi + 110;
if (sex == "男")
{
if (k1 <= 3 && k1 >= -3)
{
Console.WriteLine("您的体重是正常的！");
}
else if (k1 > 3)
{
Console.WriteLine("您需要减肥了！");
}
else
{
Console.WriteLine("您需要增肥了！");
}
}
else if (sex == "女")
{
if (k2 >= -3 && k2 <= 3)
{
Console.WriteLine("您的体重是正常的！");
}
else if (k2 > 3)
{
Console.WriteLine("您需要减肥了！");
}
else
{
Console.WriteLine("您需要增肥了！");
}
}
else
{
Console.WriteLine("输入错误！");
}
break;
}
Console.ReadLine();