1             double renShu = 80000;
 2             int year =2006;
 3             while (renShu <= 200000) //循环条件
 4             {
 5                 year++;
 6                 renShu += renShu * 0.25;//与循环条件建立关系,每年递增的人数
 7                 Console.WriteLine("第{0}年人数增长到\trenShu = {1}", year, renShu);
 8                             }
 9             Console.WriteLine("预计到{0}年人数达到{1}人", year , renShu);
10             Console.ReadKey();

 1             int sum = 2;
 2             for (int i = 3; i <= 100; i += 2)
 3             {
 4                 //int n = (int)Math.Sqrt(i); //平提高效率
 5                 int n = (int)i / 2;//求一个数的一半是否能被2到小于自身小1的数整除
 6                 bool b = true;
 7                 for (int j = 2; j <= n; j++) //j=2 从2开始除i
 8                 {
 9                     if (i % j == 0)
10                     {
11                         b = false;
12                         break;
13                     }
14                 }
15                 if (b)
16                 {
17                     sum += i;
18                     Console.WriteLine("sum = {0} i = {1}", sum, i);
19                 }
20             }
21             Console.ReadKey();

1             string name = "老赵";
2             String result = name == "老赵" ? "帅的掉渣了" : "山炮掉渣了";

            Random num1 = new Random();//创建随机对象
            int num2 = num1.Next(1, 11); //随机1-10范围内的数