while循环

基本结构

while(){ 循环体执行语句 }

2. 如何控制循环次数

通过改变循环判断条件的结果，让其循环到一定值的时候会不满足则跳出循环，执行次数变有限了

for循环

for(初始值；表达式；增量){ 循环体 }

do...while循环

do{ 循环体 }while(表达条件)；

循环中的break和continue

1. break：跳出当前整个循环

2. continue：跳出当前这一次循环，继续执行下一次循环的内容 ` /* string day = "2"; switch (day) { case "2": Console.WriteLine(); break; }/ //while循环 / while (true) { Console.WriteLine(1); **////

                  }*/
       //有序循环 让判断条件变成假
       // i <10 =>i++ 
       /*            int i = 10;
                   while (i > 2)
                   {
                       Console.WriteLine(i);
                       i--;//循环8次
                   }*/
       /*            Console.WriteLine("请输入整数n");
                   int n=Convert.ToInt32(Console.ReadLine());
                   int i=1;
                   int sum=0;
                   while (i<=n)
                   {
   
                       sum+= i;
                       i++;
   
                       Console.WriteLine(sum); 
                   }*/
       /*            Console.WriteLine("请输入n");
                   int n = Convert.ToInt32(Console.ReadLine());
                   int i = 0;
                   while (n != 1)
                   {
                       if (n % 2 == 1)
                       {
                           n = n * 3 + 1;
                       }
                       else
                       {
                           n /= 2;
                       }
                       i++;
   
                   }
                   Console.WriteLine(i);*/
   
   
       /*            double age1 = 0;
                   Console.WriteLine("学生的个数");
                   int num=Convert.ToInt32(Console.ReadLine());
                   int num2 = num;
                   double sum = 0.0;
                   Console.WriteLine("学生的年龄");
                   int age=Convert.ToInt32(Console.ReadLine());
       */
   
   
   
   
       //for循环
       /*  int num3 = 1;
         for (; num3 < 5; num3++)
         {
             Console.WriteLine(num3);
         }*/
   
   
       /*            Console.WriteLine("输如整数n");
                   int n = Convert.ToInt32(Console.ReadLine());
                   Console.WriteLine("输入整数m");
                   int m = Convert.ToInt32(Console.ReadLine());
                   int s = 0;
                   int t=0 ;
                   if (n > m)
                   {
                       n = m;
                       m = t;
                   }
                   for (; n <= m; n++)
                   {
   
                       if (n % 17 == 0)
                       {
                           s += n;
                       }
                   }
                   Console.WriteLine(s);*/
   
   
   
       //do while 循环 先执行do中语句再循环
       /*          int num7 = 1;
                 do
                 {
                     Console.WriteLine(num7);
                 } while (num7 < 10);*/
   
   
       /*            Console.WriteLine("输入一个整数a");
                   int a=Convert.ToInt32(Console.ReadLine());       
                   Console.WriteLine("输入一个整数n");
                   int n=Convert.ToInt32(Console.ReadLine());
                   int sum = 0;
                   for(int i=1; i<=n; i++)
                   {
                       sum *=a;
                   }
                   Console.WriteLine(sum);*/
       /*            double high = Convert.ToDouble(Console.ReadLine());
                   double count = 0;
                   for(int i=1;i<=10;i++)
                   {
                       count += high;
                       high = high / 2;
                       count = count + high;
   
                   }
                   Console.WriteLine("反弹的高度{0},经过{1}米", high,count);
               
       */
       /*       for(int d = 100; d <= 999; d++)
                   {
                       int ge = d % 10;
                       int shi = d /10%10;
                       int bai = d  /100 ;
                       if (ge * ge*ge+ bai * bai *bai+ shi * shi*shi == d)
                       {
                           Console.WriteLine("水仙花数{0}为",d);
   
                       }
                   }*/
       /*            Console.WriteLine("请输入班级人数");
                   int count = Convert.ToInt32(Console.ReadLine());
                   int sum = 0;
                   int i = 1;
                   while (i <= count)
                   {
                       Console.WriteLine("请同学的分数{0}",i);
                       int n = Convert.ToInt32(Console.ReadLine());
                       sum += n;
                       i++;
   
                   }
                   Console.WriteLine("同学数量为{0},总分为{1},平均成绩为{2}",count,sum,sum/count);*/
   
       Console.WriteLine("请输入班级人数");
       int count = Convert.ToInt32(Console.ReadLine());
       int sum = 0;
       for (int i = 1; i<= count; i++)
       {
           Console.WriteLine("请输入同学{0}的分数", i);
           int n = Convert.ToInt32(Console.ReadLine());
           sum += n;
                       
       }
       Console.WriteLine("同学数量为{0},总分为{1},平均成绩为{2}", count, sum, sum / count);
   

`