for循环语句之求和，阶乘，求偶，求n次篮球蹦起高度

for (int i = 1;/*初始条件*/i <= 100;/*循环条件*/i++/*状态改变*/)
            { 
            //循环体，执行代码；（break;跳出循环体）
             }

            Console.WriteLine("请输入一个数：");
            int a = Convert.ToInt32(Console.ReadLine());

            int sum = 0;

            for (int i = 1; i <= a; i++)
            {
                sum = sum + i;
            }
            Console.WriteLine("您输入的这个数的累加和为：" + sum);

Console.WriteLine("请输入一个数：");
            int a = Convert.ToInt32(Console.ReadLine());

            int jc = 1;

            for (int i = 1; i <= a; i++)
            {
                jc = jc * i;
            }

            Console.WriteLine("您输入的这个数的阶乘为：" + jc);

            int cj = 1;

            for (int i = 1; i <= 9; i++)
            {
                for (int j = 1; j <= 9; j++)
                {
                    cj = i * j;
                    Console.Write(i + "*" + j + "=" + cj + "   ");
                }
                Console.WriteLine();

            }

//求100以内的所有偶数
            for (int i = 0; i <= 100; i++)
            {
                if (i % 2 == 0)//%代表求余
                {
                    Console.WriteLine(i);
                }
            }

 //蓝球弹起的高度
            Console.WriteLine("请输入次数：");
            int a = Convert.ToInt32(Console.ReadLine());

            double gao = 5;

            for (int i = 1; i <= a; i++)
            {
                if (i > 5)
                {
                    gao = 0;
                }
                else
                {
                    gao = gao / 2;
                }
            }

            Console.WriteLine("第" + a + "次弹起的高度为：" + gao.ToString());