哪位大神指导下，感激不尽了
 static void Main(string[] args)
        {
            double a=5;
            double b=3;
            double a1;
            double a2;
            int cishu = 1;
            while (cishu <= 10)
            {
                if (cishu == 1)
                {
                    a1 = a * b / (b - a);
                }
                else
                {
                    a2 = a1 + b;
                }
                cishu = cishu + 1;
            }         
        }

double a1 = 0;

定义一个变量的时候最好给赋个初值（建议a1，a2都赋初值），有些语言要求比较严格
这里的a1只是定义没有赋值

[此贴子已经被作者于2017-8-15 09:29编辑过]