今天学了if 条件语句和作用域。作用域可以用一句话来概括:儿子可以用爹的所有东西,爹不可以用儿子的任何东西。If条件语句我用几个练习题来解释。

1、“请输入年份:”
判断是否是闰年,“xxxx年是闰年”,“xxxx年不是闰年”

namespace _2017_2_21
{
    class Program
    {
        static void Main(string[] args)
        {
            Console.Write("请输入年份:");
            int a=Convert.ToInt32(Console.ReadLine());
            if(a>0&&a<9999&&a%4==0&&a%100!=0||a%400==0)
            { 
                Console.Write(a+"年是闰年");
            }
            else
            {
                Console.Write(a+"年不是闰年");
            }
            Console.ReadLine();
        }
    }
}

2、“请输入您的分数:”
小于0,大于100,“输入的分数有误!”
大于0,小于10,“不及格!学渣!”
小于60,“不及格!继续努力!”
大于等于60,“恭喜你!及格了!”
大于等于90,“学霸!很厉害!”

namespace _2017_2_21
{
    class Program
    {
        static void Main(string[] args)
        {
            Console.Write("请输入您的分数:");
            Double a=Convert.ToDouble(Console.ReadLine());
            if(a<0||a>100)
            {
                Console.WriteLine("输入的分数有误!");
            }
            if(a>0&&a<10)
            {
                Console.WriteLine("不及格!学渣!");
            }
            if(a>=10&&a<60)
            {
                Console.WriteLine("不及格!继续努力!");
            }
            if(a>=60&&a<90)
            {
                Console.WriteLine("恭喜你!及格了!");
            }
            if(a>=90&&a<=100)
            {
                Console.WriteLine("学霸!很厉害!");
            }
            Console.ReadLine();
        }
    }
}

3、猜拳
“请输入您的手势(石头/剪子/包袱):”
“用户赢了” “电脑赢了” “平局”

namespace _2017_2_21
{
    class Program
    {
        static void Main(string[] args)
        {
            Console.Write("请输入您的手势(石头/剪子/包袱):");
            String you=Console.ReadLine();
            Random n = new Random();
            int a = n.Next(1, 4);
            Console.WriteLine(a);

            if ((you == "石头" && a == 2) || (you == "剪子" && a == 3) || (you == "包袱" && a == 1))
            {
                Console.Write("你赢了");
            }
            else if((you=="石头"&&a==1)||(you=="剪子"&&a==2)||(you=="包袱"&&a==3))
            {
                Console.Write("平了");
            }
            else 
            {
                Console.Write("你输了");
            }
            Console.ReadLine();
        }
    }
}

4、人工智能对话
如果说的是同一句话,不一定要回复同一句

namespace _2017_2_21
{
    class Program
    {
        static void Main(string[] args)
        {
            Console.WriteLine("请说话:");
            String a = Console.ReadLine();
            Random n = new Random();
            int g = n.Next(0, 5);
            if (g == 1)
            {
                Console.WriteLine("哈哈");
            }
            else if (g == 2)
            {
                Console.WriteLine("嘻嘻");
            }
            else if (g == 3)
            {
                Console.WriteLine("你好");
            }
            else if (g == 4)
            {
                Console.WriteLine("汪汪");
            }
            else if (g == 0)
            {
                Console.WriteLine("hello");
            }
            Console.ReadLine();
        }
    }
}

1、“请输入年份:”(1-9999)
“请输入月份:”(1-12)
“请输入日期:”(要判断大小月,判断闰年)
判断输入的时间日期是否正确

2、计算输入的时间是当前这一年的第几天

 

namespace _2017_2_22作业1
{
    class Program
    {
        static void Main(string[] args)
        {int year, month, date,num;
            Console.WriteLine("请输入年份:(1-9999)");
            year=Convert.ToInt32(Console.ReadLine());
            if (year >= 1 && year <= 9999)
            {
                Console.WriteLine("请输入月份:");
                month = Convert.ToInt32(Console.ReadLine());
                if (month >= 1 && month <= 12)
                {
                    Console.WriteLine("请输入日期:");
                    date = Convert.ToInt32(Console.ReadLine());
                    if (month == 1 || month == 3 || month == 5 || month == 7 || month == 8 || month == 10 || month == 12 && date >= 1 && date <= 31)
                    {
                        Console.WriteLine("您输入的日期格式正确");
                        if(month==1)
                        {
                            num = date;
                            Console.WriteLine("您输入的日期是当年的第"+num+"天");
                        }
                        if ((year >= 1 && year <= 9999 && year % 4 == 0 && year % 100 != 0 || year % 400 == 0) && month == 3)
                        {
                            num = 31 + 29 + date;
                            Console.WriteLine("您输入的日期是当年的第" + num + "天");
                           
                        }
                        else if ((year >= 1 && year <= 9999 && year % 4 != 0 || year % 100 == 0 || year % 400 != 0) && month == 3)
                        {
                            num = 31 + 28 + date;
                            Console.WriteLine("您输入的日期是当年的第" + num + "天");
                        }
                        if ((year >= 1 && year <= 9999 && year % 4 == 0 && year % 100 != 0 || year % 400 == 0) && month == 5)
                        {
                            num = 31 + 29 + 31+30+date;
                            Console.WriteLine("您输入的日期是当年的第" + num + "天");
                        }
                        else if ((year >= 1 && year <= 9999 && year % 4 != 0 || year % 100 == 0 || year % 400 != 0) && month == 5)
                        {
                            num = 31 + 28 + 31 + 30 +  date;
                            Console.WriteLine("您输入的日期是当年的第" + num + "天");
                        }
                        if ((year >= 1 && year <= 9999 && year % 4 == 0 && year % 100 != 0 || year % 400 == 0) && month == 7)
                        {
                            num = 31 + 29 + 31 + 30 +31+30+ date;
                            Console.WriteLine("您输入的日期是当年的第" + num + "天");
                        }
                        else if ((year >= 1 && year <= 9999 && year % 4 != 0 || year % 100 == 0 || year % 400 != 0) && month == 7)
                        {
                            num = 31 + 28 + 31 + 30 + 31 + 30 + date;
                            Console.WriteLine("您输入的日期是当年的第" + num + "天");
                        }

                        if ((year >= 1 && year <= 9999 && year % 4 == 0 && year % 100 != 0 || year % 400 == 0) && month == 8)
                        {
                            num = 31 + 29 + 31 + 30 + 31 + 30 +31+ date;
                            Console.WriteLine("您输入的日期是当年的第" + num + "天");
                        }
                        else if ((year >= 1 && year <= 9999 && year % 4 != 0 || year % 100 == 0 || year % 400 != 0) && month == 8)
                        {
                            num = 31 + 28 + 31 + 30 + 31 + 30 + 31 +  date;
                            Console.WriteLine("您输入的日期是当年的第" + num + "天");
                        }

                        if ((year >= 1 && year <= 9999 && year % 4 == 0 && year % 100 != 0 || year % 400 == 0) && month == 10)
                        {
                            num = 31 + 29 + 31 + 30 + 31 + 30 +31+31+30+ date;
                            Console.WriteLine("您输入的日期是当年的第" + num + "天");
                        }
                        else if ((year >= 1 && year <= 9999 && year % 4 != 0 || year % 100 == 0 || year % 400 != 0) && month == 10)
                        {
                            num = 31 + 28 + 31 + 30 + 31 + 30 + 31 + 31 + 30 +  date;
                            Console.WriteLine("您输入的日期是当年的第" + num + "天");
                        } 
                        if ((year >= 1 && year <= 9999 && year % 4 == 0 && year % 100 != 0 || year % 400 == 0) && month == 12)
                        {
                            num = 31 + 29 + 31 + 30 + 31 + 30+31+31+30+31+30+ date;
                            Console.WriteLine("您输入的日期是当年的第" + num + "天");
                        }
                        else if ((year >= 1 && year <= 9999 && year % 4 != 0 || year % 100 == 0 || year % 400 != 0) && month == 12)
                        {
                            num = 31 + 28 + 31 + 30 + 31 + 30+31+31+30+31+30+date;
                            Console.WriteLine("您输入的日期是当年的第" + num + "天");
                        }
                    }
                    
                    else if ((month == 4 || month == 6 || month == 9 || month == 11) && date >= 1 && date <= 30)
                    {
                        Console.WriteLine("您输入的日期格式正确");
                        if ((year >= 1 && year <= 9999 && year % 4 == 0 && year % 100 != 0 || year % 400 == 0) && month == 4)
                        {
                            num = 31 + 29 + 31+ date;
                            Console.WriteLine("您输入的日期是当年的第" + num + "天");
                        }
                        else if ((year >= 1 && year <= 9999 && year % 4 != 0 || year % 100 == 0 || year % 400 != 0) && month == 4)
                        {
                            num = 31 + 28 + 31 +  date;
                            Console.WriteLine("您输入的日期是当年的第" + num + "天");
                        }
                        if ((year >= 1 && year <= 9999 && year % 4 == 0 && year % 100 != 0 || year % 400 == 0) && month == 6)
                        {
                            num = 31 + 29 + 31 + 30 +31+date;
                            Console.WriteLine("您输入的日期是当年的第" + num + "天");
                        }
                        else if ((year >= 1 && year <= 9999 && year % 4 != 0 || year % 100 == 0 || year % 400 != 0) && month == 6)
                        {
                            num = 31 + 28 + 31 + 30 + 31 +  date;
                            Console.WriteLine("您输入的日期是当年的第" + num + "天");
                        }
                        if ((year >= 1 && year <= 9999 && year % 4 == 0 && year % 100 != 0 || year % 400 == 0) && month == 9)
                        {
                            num = 31 + 29 + 31 + 30 + 31 + 30+31+31+ date;
                            Console.WriteLine("您输入的日期是当年的第" + num + "天");
                        }
                        else if ((year >= 1 && year <= 9999 && year % 4 != 0 || year % 100 == 0 || year % 400 != 0) && month == 9)
                        {
                            num = 31 + 28 + 31 + 30 + 31 + 30 + 31 + 31 +  date;
                            Console.WriteLine("您输入的日期是当年的第" + num + "天");
                        }
                        if ((year >= 1 && year <= 9999 && year % 4 == 0 && year % 100 != 0 || year % 400 == 0) && month ==11)
                        {
                            num = 31 + 29 + 31 + 30 + 31 + 30 + 31 + 31 + 30+31+ date;
                            Console.WriteLine("您输入的日期是当年的第" + num + "天");
                        }
                       
                        
                       
                        else if ((year >= 1 && year <= 9999 && year % 4 != 0 || year % 100 == 0 || year % 400 != 0) && month == 11)
                        {
                            num = 31 + 28 + 31 + 30 + 31 + 30 + 31 + 31 + 30 + 31 +  date;
                            Console.WriteLine("您输入的日期是当年的第" + num + "天");
                        }
                    }
                    else if ((year >= 1 && year <= 9999 && year % 4 == 0 && year % 100 != 0 || year % 400 == 0) && month == 2 && date >= 1 && date <= 29)
                    {
                        Console.WriteLine("您输入的日期格式正确");
                        num = 31 + 29;
                        Console.WriteLine("您输入的日期是当年的第" + num + "天");
                    }
                    else if ((year >= 1 && year <= 9999 && year % 4 != 0 || year % 100 == 0 || year % 400 != 0) && month == 2 && date >= 1 && date <= 28)
                    {
                        Console.WriteLine("您输入的日期格式正确");
                        num = 31 + 28;
                        Console.WriteLine("您输入的日期是当年的第" + num + "天");
                    }
                    

                    else
                    {
                        Console.WriteLine("您输入的日期格式不对");
                    }
                }
                else
                {
                    Console.WriteLine("您输入的月份格式错误");
                }
            }
            else 
            {
                Console.WriteLine("您输入的年份格式错了");
            }
            Console.ReadLine();
            

        }
    }
}

3、标准体重
男士体重 = 身高 - 100 +-3
kg cm
女士体重 = 身高 - 110 +-3

namespace _2017_2_22标准体重
{
    class Program
    {
        static void Main(string[] args)
        {Console.WriteLine("请输入您的性别");
            String sex=Console.ReadLine();
            Console.WriteLine("请输入您的体重");
            int weight = Convert.ToInt32(Console.ReadLine());
            Console.WriteLine("请输入您的身高");
            int height =Convert.ToInt32( Console.ReadLine());
            if (sex == "男" && (height - weight - 100 >= -3 || height - weight - 100 <= 3))
            {
                Console.WriteLine("您的体重是标准体重");
            }
            else 
            {
                if (height - weight - 100 < -3)
                {
                    Console.WriteLine("您超重");
                }
                if (height - weight - 100>3)
                {
                    Console.WriteLine("您偏瘦");
                }
                Console.ReadLine();
            }
            if (sex == "女" &&( height - weight - 110 >= -3 || height - weight - 110 <= 3))
            {
                Console.WriteLine("您的体重是标准体重");
            }
            else 
            {
                if (height - weight - 110 < -3)
                {
                    Console.WriteLine("您超重");
                }
                if (height - weight - 110 > 3)
                {
                    Console.WriteLine("您偏瘦");
                }
                Console.ReadLine();
            }
        }
    }
}

4、猜拳将用户的手势和电脑的手势输出出来

namespace _2017_2_22猜拳游戏显示手势
{
    class Program
    {
        static void Main(string[] args)
        {
            Console.Write("请输入您的手势(石头/剪子/包袱):");
            String you = Console.ReadLine();
            Random n = new Random();
            int a = n.Next(1, 4);
            
            if (a==1)
            {
                Console.WriteLine("石头");
            }
            if (a == 2)
            {
                Console.WriteLine("剪子");
            }
            if (a == 3)
            {
                Console.WriteLine("包袱");
            }

            

            if ((you == "石头" && a == 2) || (you == "剪子" && a == 3) || (you == "包袱" && a == 1))
            {
                Console.Write("你赢了");
            }
            else if ((you == "石头" && a == 1) || (you == "剪子" && a == 2) || (you == "包袱" && a == 3))
            {
                Console.Write("平了");
            }
            else
            {
                Console.Write("你输了");
            }
            Console.ReadLine();
        }
    }
}

5、“请输入24小时制的时间:”
0-24 如果超出“时间输入有误”

namespace _2017_2_22时间24小时制转变成12小时制
{
    class Program
    {
        static void Main(string[] args)
        {
            Console.WriteLine("请输入24小时制的时间:");
            int a =Convert.ToInt32( Console.ReadLine());
            if(a>24||a<0)
            {
                Console.WriteLine("输入的时间有误");
            }
            if(a<=12&&a>6)
            {
                Console.WriteLine("上午"+a+"点");
            }
            if(a<=6)
            {
                Console.WriteLine("凌晨" + a + "点");
            }
            int b = a - 12;
            if(a>12&&a<24)
            {
                Console.WriteLine("下午" + b + "点");
            }
            if(a==24)
            {
                Console.WriteLine("凌晨0点");
            }

            Console.ReadLine();
        }
    }
}