三月12号的 问题特别多

今天讲的内容有些多主要是类的复习以及数组的练习，都是一些比较复杂的题型的，需要多加练习才可以的

首先是关于截取的练习输入身份证号码截取生日

//输入身份证号接受生日
            Console.Write("请输入你的身份证号");
            string a = Console.ReadLine();           
            if (a.Length== 18)
            {
                string c = a.Substring(6,4);
                string d = a.Substring(11, 1);
                string e = a.Substring(12,2);
                Console.WriteLine(""+c+"年"+d+"月"+e+"日");
            }
            else
            {
                Console.WriteLine("有误");
            }
            Console.ReadLine();

 

   //邮箱格式
            //1.有且只有一个@，
            //2.不能以@开头
            //@之后至少有一个.
            //@和.不能靠在一起
            //不能以.结尾
            Console.Write("请输入你的邮箱");
            string mail = Console.ReadLine();
            bool a = mail.Contains("@");//判断是否包含@
            if (a == true)
            {
                 int b = mail.IndexOf("@");
                 int c = mail.LastIndexOf("@");//判断只有一个@
                 if (b == c)
                 {
                     if (b != 0)//不以@开头，索引第一位为0
                     {
                         string mail1 = mail.Substring(b);//从@开始截取
                        if(mail1.Contains(".")) //从@截取的mail1中是不是含有.
                        {
                            int d = mail1.IndexOf(".");//mail1中.的索引
                            if (d != 1)//不是和@紧挨的
                            {
                                int e = mail.LastIndexOf(".");//最后一个.的索引号
                                if(e!=mail.Length-1)//长度减一等于索引
                                {
                                    Console.WriteLine("输入正确");
                                }
                                else
                                {
                                  Console.WriteLine("输入有误");
                                }
                            }
                            else
                            {
                                Console.WriteLine("输入有误");
                            }
                        }
                        else
                        {
                          Console.WriteLine("输入有误");
                        }
                     }

                     else
                     {
                         Console.WriteLine("输入有误");
                     }
                 }
                 else
                 {
                     Console.WriteLine("输入有误");
                 }
            }
            else
            {
                Console.WriteLine("输入有误");
            }
            Console.ReadLine();

输出结果的展示

关于验证码的第一个练习题，错了就是错了的形式

 string s = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
            Random ran = new Random();
            string biao = "";
            for (int i=0;i<4 ;i++ )
            {
                biao += s.Substring(ran.Next(s.Length), 1);
            }
            Console.WriteLine(biao);
            Console.Write("请输入验证码");
            string shu = Console.ReadLine();
            if (biao.ToLower() == shu.ToLower())
            {
                Console.WriteLine("输入正确");
            }
            else
            {
                Console.WriteLine("输入错误");
            }
            Console.ReadLine();

  

一般的验证码都是错了清屏再重新输入的以下就是此案例的补充

 //验证码输入错误后重新输入
            string s = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
            Random ran = new Random();
            for (; ; )
            {
                string biao = "";
                for (int i = 1; i <= 4; i++)
                {
                    biao += s.Substring(ran.Next (s.Length),1);
                }
                Console.WriteLine(biao);
                Console.Write("请输入验证码");
                string shu = Console.ReadLine();
                if (shu.ToLower() == biao.ToLower())
                {
                    Console.WriteLine("输入正确");
                    break;
                }
                else
                {
                    Console.Clear();
                    Console.WriteLine("输入有误重新输入");                   
                }             
            }

            Console.ReadLine();

数组：具有相同类型的若干变量按有序的形式组织起来的一种形式。这些按序排列的同类数据元素的集合称为数组。
定义数组
int[] 变量名 = new int [n];

string[] myStringArray = new string[6];

int[] myArray = new int[] {1, 3, 5, 7, 9};
取值：int a = myArray[0];

一维数组的两种表达形式

   //int[] shuzu = new int[5];
            ////索引从0开始
            ////赋值
            //shuzu[0] = 1;
            //shuzu[1] = 2;
            //shuzu[2] = 3;
            //shuzu[3] = 4;
            //shuzu[4] = 5;
            //shuzu[5] = 6;//不可以超出上限
            //Console.WriteLine(shuzu[3]);


            //第二种定义
            //int[] shuzu = new int[] { 1, 2, 3, 4, 5 };
            //Console.WriteLine(shuzu[4]);

            //从控制台输入10个人的年龄放入数组
            //将十个人的年龄求总和

            int[] age = new int[10];
            int sum = 0;
            for (int i = 0; i < 10; i++)
            {
                Console.Write("第"+(i+1)+"个人的年龄是");
                age[i] = int.Parse(Console.ReadLine());
                sum+=age[i];
            }
            Console.WriteLine(sum);
            Console.ReadLine();

注意【】里面的是索引，不能超出上限

  //输入人名放进数组，输出第5个的姓名

            //输出第5个首先要求比5要大才可以
            Console.Write("请输入班级的人数");
            int a = int.Parse(Console.ReadLine());
            string[] name = new string[a];
            for (int i = 0; i < a; i++)
            {
                Console.Write("第"+(i+1)+"个人的姓名是");
                name[i] = Console.ReadLine();
            }
            Console.WriteLine(name[4]);
            Console.ReadLine();

   Console.Write("请输入班级的人数");
            int a = int.Parse(Console.ReadLine());
            double[] b = new double[a];
            double sum = 0;
            
            for (int i=0;i<a;i++ )
            {
                Console.Write("第"+(i+1)+"个人的成绩是：");
                b[i] = double.Parse(Console.ReadLine());
                sum += b[i];
            }
            Console.WriteLine(sum);
            Console.WriteLine("平均分为"+sum/a);
            Console.ReadLine();

  //二维数组
            //int[,] shuzu = new int[3, 4];
            //int[,] shuzu = new int[,] {
            //{1,2,3,4},
            //{5,6,7,8},
            //{6,7,8,9}
            //};

 string[,] shuzu = new string[,]{
            {"  ","■","■","■","■","■","  "},
            {"  ","  ","  ","■","  ","  ","  "},
            {"  ","  ","  ","■","  ","  ","  "},
            {"  ","■","■","■","■","■","  "},
            {"  ","  ","  ","■","  ","  ","  "},
            {"  ","  ","  ","■","  ","  ","  "},
            {"■","■","■","■","■","■","■"}    
            };
            for (int i=0; i < 7; i++)
            {
                for (int j = 0; j < 7; j++)
                {
                    Console.Write(shuzu[i,j]);
                }
                Console.WriteLine();
            }
            Console.ReadLine();

 

 //输入班级人数，将每个人的
            //语文，数学，英语成绩输入二维数组
            Console.Write("请输入班级人数：");
            int a = int.Parse(Console.ReadLine());
            double[,] shuzu = new double[a, 3];

            for (int i = 0; i < a; i++)
            {
                for (int j = 0; j < 3; j++)
                {
                    if (j == 0)
                    {
                        Console.Write("请输入第" + (i + 1) + "个人的语文成绩：");
                    }
                    if (j == 1)
                    {
                        Console.Write("请输入第" + (i + 1) + "个人的数学成绩：");
                    }
                    if (j == 2)
                    {
                        Console.Write("请输入第" + (i + 1) + "个人的英语成绩：");
                    }
                    shuzu[i, j] = double.Parse(Console.ReadLine());
                }
            }
            Console.ReadLine();

以上是自己的练习

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原文地址：https://www.cnblogs.com/Duriyya/p/5269269.html