0722语句

//语句的分类
            //顺序语句，分支语句（选择语句） ，循环语句

            //分枝
            //格式1   if（）{}
            //int a = 6;
            //  if(a<=100&&a>=0)
            //  {
            //      Console.WriteLine("这个数是100以内的数");

            //  }
            //  Console.WriteLine(a);
            //  Console.ReadLine();

            //格式2  if(){} else{}
            //如果if满足，走if
            //如果if不满足，就一定走else

            //Console.Write("请输入一个数字");
            //int a = int.Parse(Console.ReadLine());
            //if (a >= 10 && a < 100)
            //{
            //    Console.WriteLine("您输入的是一个两位整数");
            //}
            //else
            //{
            //if(a<10){
            //    Console.Write("您输入的不是两位数");
            //}
            //    else
            //    {
            //     Console.WriteLine("您输入的数大于等于100");
            //    }
            //}
            //    Console.ReadLine();

            //格式3 if(){}else   if(){}    else{}   多选一
            //只要上面有一个if或else if满足，就执行
            //从它开始下面不再判断
            //Console.Write("请输入一个月份：");
            //int a = int.Parse(Console.ReadLine());
            //if (a > 2 && a < 6)
            //{
            //    Console.WriteLine("您输入的是春天的月份");
            //}
            //else if (a > 5 && a < 9)
            //{
            //    Console.WriteLine("您输入的是夏天的月份");
            //}
            //else if (a > 8 && a < 12)
            //{
            //    Console.WriteLine("您输入的是秋天的月份");
            //}
            //else if (a == 12 || a == 1 || a == 2)
            //{
            //    Console.WriteLine("您输入的是冬天的月份");
            //}

            //else
            //{
            //    Console.WriteLine("您输入的有误");
            //}
            //    Console .ReadLine();

            //格式4  if的嵌套
            //首先规定大的范围，再进去判断小的情况
            //    Console.Write("请输入一个月份：");
            //    int a = int.Parse(Console.ReadLine());
            //    if(a>0&&a<13)
            //{
            //    if (a > 2 && a < 6)
            //{
            //    Console.WriteLine("您输入的是春天的月份");
            //}
            //else if (a > 5 && a < 9)
            //{
            //    Console.WriteLine("您输入的是夏天的月份");
            //}
            //else if (a > 8 && a < 12)
            //{
            //    Console.WriteLine("您输入的是秋天的月份");
            //}
            //    else if (a == 12 || a == 1 || a == 2)
            //{
            //        Console.WriteLine("您输入的是冬天的月份");
            //}
            //}
            //else
            //{
            // Console.WriteLine("您输入有误");
            //}
            // Console.ReadLine();

            //输入学生姓名，输入考试成绩
            //若是100，【恭喜**，满分通过！】
            //若是大于等于80小于100.【**，你很优秀，请继续保持】
            //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】
            //小于50【**你是笨蛋吗】
            //Console.Write("请输入您的姓名：");
            //string name = Console.ReadLine();
            //Console.Write("请输入您的成绩：");
            //double a = double.Parse(Console.ReadLine());
            //if (a == 100)
            //{
            //    Console.WriteLine("恭喜" + name + ",满分通过！");
            //}
            //else if (a >= 80 && a < 100)
            //{
            //    Console.WriteLine(name + "，你很优秀，请继续保持！");
            //}
            //else if (a >= 60 && a < 80)
            //{
            //    Console.WriteLine(name + "成绩良好");
            //}
            //else if (a >= 50 && a < 60)
            //{
            //    Console.WriteLine(name + "就差一点点，下次一定要至少及格！");
            //}
            //else
            //{
            //    Console.WriteLine(name + "你是笨蛋吗？");
            //}
            //Console.ReadLine();

            //请输入一个年份，判断年份是不是闰年
            //year%4==0&&year%100!=0
            //year%400==0
            //Console.Write("请输入一个年份：");
            //int year = int.Parse(Console.ReadLine());
            //if(year>=0&&year<=9999)
            //{
            //    if (year % 4 == 0 && year % 100 != 0||year%400==0 )
            //    {
            //            Console.WriteLine("您输入的是闰年！");

            //    }
            //    else
            //    {
            //        Console.WriteLine("您输入的不是闰年！");
            //    }
            //}
            //else
            //{
            //    Console.WriteLine("输入有误！");
            //}
            //Console.ReadLine();

            //分别输入年月日，判断日期格式是否正确
            //Console.Write("请输入年份:");
            //int year = int.Parse(Console.ReadLine());
            //if (year >= 0 && year <= 9999)
            //{
            //    Console.Write("请输入月份：");
            //    int month = int.Parse(Console.ReadLine());
            //    if (month >= 1 && month <= 12)
            //    {
            //        Console.Write("请输入日期：");
            //        int day = int.Parse(Console.ReadLine());
            //        if (day >= 1 && day <= 31)
            //        {
            //            if (month == 1 || month == 3 || month == 5 || month == 7 || month == 8 || month == 10 || month == 12)
            //            {
            //                Console.WriteLine("您输入的日期正确，日期为：" + year + "年" + month + "月" + day + "日。");
            //            }
            //            else if (month == 4 || month == 6 || month == 9 || month == 11)
            //            {
            //                string d = day <= 30 ? "您输入的日期正确，日期为：" + year + "年" + month + "月" + day + "日。" : "日期格式有误！";
            //                Console.WriteLine(d);
            //            }
            //            else if (month == 2)
            //            {
            //                if (day >= 30)
            //                {
            //                    Console.WriteLine("日期格式有误！");
            //                }
            //                else if (day == 28)
            //                {
            //                    Console.WriteLine("您输入的日期正确，日期为：" + year + "年" + month + "月" + day + "日。");
            //                }

            //                else if (day == 29)
            //                {
            //                    if (year % 4 == 0 && year % 100 != 0 || year % 400 == 0)
            //                    {
            //                        Console.WriteLine("您输入的日期正确，日期为：" + year + "年" + month + "月" + day + "日。");
            //                    }
            //                    else
            //                    {
            //                        Console.WriteLine("日期格式有错！");
            //                    }
            //                }
            //            }

            //            else
            //            {
            //                Console.WriteLine("日期格式有错！");
            //            }

            //        }
            //        else
            //        {
            //            Console.WriteLine("您输入的日期有误！");
            //        }
            //    }
            //    else
            //    {
            //        Console.WriteLine("您输入的月份有误！");
            //    }
            //}
            //else
            //{
            //    Console.WriteLine("您输入的年份有误！");
            //}
            //Console.ReadLine();

            //1.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.Write("请输入a的值：");
            //double a = double.Parse(Console.ReadLine());
            //if (a != 0)
            //{
            //    Console.Write("请输入b的值：");
            //    double b = double.Parse(Console.ReadLine());
            //    Console.Write("请输入c的值：");
            //    double c = double.Parse(Console.ReadLine());
            //    double e = b * b - 4 * a * c;
            //    if (e < 0)
            //    {
            //        Console.WriteLine("方程无实根");
            //    }
            //    else if (e > 0)
            //    {
            //        Console.WriteLine("方程有两个实根，分别为x1=" + ((-b + Math.Sqrt(e)) / (2 * a)) + ",x2=" + ((-b - Math.Sqrt(e)) / (2 * a)));
            //    }
            //    else
            //    {
            //        Console.WriteLine("方程有两个相等实数根，为x1=x2=" + ((-b + Math.Sqrt(e)) / (2 * a)));
            //    }
            //}
            //else
            //{
            //    Console.WriteLine("非一元二次方程");
            //}
            //Console.ReadLine();

            //2.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.Write("请输入x的值：");
            //double x = double.Parse(Console.ReadLine());
            //if(x<1)
            //{
            //    Console.WriteLine("得到的y值为："+x);
            //}
            //else if (x >= 1 && x < 10)
            //{
            //    Console.WriteLine("得到的y值为：" + (2 * x - 1));
            //}
            //else
            //{
            //    Console.WriteLine("得到的y值为："+(3*x-11));
            //}
            //Console.ReadLine();

            //3.输入整数a和b,若a2+b2大于100,则输出a2+b2百位以上数字,否则输出两数之和
            //Console.Write("请输入a的值：");
            //double a = double.Parse(Console.ReadLine());
            //Console.Write("请输入b的值：");
            //double b = double.Parse(Console.ReadLine());
            //double c=a*a+b*b;
            //if (c > 100)
            //{
            //    Console.WriteLine(c);
            //}
            //else
            //{
            //    Console.WriteLine(a+b);
            //}
            //Console.ReadLine();

            //4.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.Write("你有房子吗？");
            //string ss = Console.ReadLine();
            //if (ss == "没有")
            //{
            //    Console.Write("你有钱吗？");
            //    string a = Console.ReadLine();
            //    if (a == "没有")
            //    {
            //        Console.Write("你有能力吗？");
            //        string b = Console.ReadLine();
            //        if (b == "没有")
            //        {
            //            Console.WriteLine("拜拜~");
            //        }
            //        else
            //        {
            //            Console.WriteLine("先赚钱再买房子再结婚！");
            //        }
            //    }
            //    else
            //    {
            //        Console.WriteLine("先买房子在结婚");
            //    }
            //}
            //else
            //{
            //    Console.WriteLine("结婚吧！");
            //}

            //Console.ReadLine();

            //switch case   多选一
            //Console.WriteLine("1.汉堡包");
            //Console.WriteLine("2.鸡腿");
            //Console.WriteLine("3.鸡米花");
            //Console.WriteLine("4.鸡肉卷");

            //Console.Write("请输入你想要的物品的编号：");
            //int a = int.Parse(Console.ReadLine());

            //switch (a)
            //{
            //    case 1:
            //        Console.WriteLine("您选择的是汉堡包！");
            //        break;//跳出：跳出最近的花括号
            //    case 2:
            //        Console.WriteLine("您选择的是鸡腿！");
            //        break;//跳出：跳出最近的花括号
            //    case 3:
            //        Console.WriteLine("您选择的是鸡米花！");
            //        break;//跳出：跳出最近的花括号
            //    case 4:
            //        Console.WriteLine("您选择的是鸡肉卷！");
            //        break;//跳出：跳出最近的花括号
            //    default://意思是相当于else，表示以上的值都不对
            //        Console.WriteLine("输入错误！");
            //        break;
            //}
            //Console.ReadLine();

           // Console.Write("请输入月份：");
           // int month = int.Parse(Console.ReadLine());
           // Console.Write("请输入日期：");
           // int day = 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;
           //  int num;
           //  switch (month)
           //  {
           //      case 1: Console.WriteLine("第" + day + "天");
           //          break;
           //      case 2: Console.WriteLine("第" + (day+m1) + "天");
           //          break;
           //      case 3: Console.WriteLine("第" + (day+m1+m2) + "天");
           //          break;
           //      case 4: Console.WriteLine("第" + (day+m1+m2+m3) + "天");
           //          break;
           //      case 5: Console.WriteLine("第" + (day+m1+m2+m3+m4) + "天");
           //          break;
           //      case 6: Console.WriteLine("第" + (day+m1+m2+m3+m4+m5) + "天");
           //          break;
           //      case 7: Console.WriteLine("第" + (day+m1+m2+m3+m4+m5+m6) + "天");
           //          break;
           //      case 8: Console.WriteLine("第" + (day+m1+m2+m3+m4+m5+m6+m7) + "天");
           //          break;
           //      case 9: Console.WriteLine("第" + (day+m1+m2+m3+m4+m5+m6+m7+m8) + "天");
           //          break;
           //      case 10: Console.WriteLine("第" + (day+m1+m2+m3+m4+m5+m6+m7+m8+m9) + "天");
           //          break;
           //      case 11: Console.WriteLine("第" + (day+m1+m2+m3+m4+m5+m6+m7+m8+m9+m10) + "天");
           //          break;
           //      case 12: Console.WriteLine("第" + (day+m1+m2+m3+m4+m5+m6+m7+m8+m9+m10+m11) + "天");
           //          break;

           //      default:
           //           Console .WriteLine("您输入的有误！");
           //          break;
           //  }
           //          Console.ReadLine();