C#编程基础 实验（7） (1-2)

1.将百分制转换成五分制，如果输入的百分制成绩超出0~100时，程序抛出异常。

代码如下：

using System;
using System.Collections;
using System.Collections.Generic; 
namespace Program
{
    class OverflowRange : ApplicationException
    {
        public OverflowRange(string msg):base(msg)
        { }
    }
    class Program
    {
       
        static void Main(string[] args)
        {
            try
            {
                Console.Write("输入一个百分数：");
                int num = Convert.ToInt32(Console.ReadLine());
                if (num < 0 || num > 100)
                {
                    throw new OverflowRange("数值不在0~100之间");
                }
                double result = (double)num * 5.0 / 100;
                Console.WriteLine("转换成五分制为：{0}", result);
            }
            catch (FormatException)
            {
                Console.WriteLine("必须输入数字");
            }
            catch (Exception e)
            {
                Console.WriteLine(e.Message);
            }
            finally
            {
                Console.ReadKey();
            }
        }
    }
    
}

2.编写一个计算阶乘的程序，当输入的数据是带小数时，引发异常。

using System;
using System.Collections;
using System.Collections.Generic; 
namespace Program
{
    class WithoutDecimal : ApplicationException
    {
        public WithoutDecimal(string msg):base(msg)
        { }
    }
    class Program
    {
       
        static void Main(string[] args)
        {
            try
            {
                Console.Write("输入一个数：");
                double num = Convert.ToDouble(Console.ReadLine());
                if (num - (int)num != 0)
                {
                    throw new WithoutDecimal("输入的数据带小数");
                }
                int sum = 1;
                for (int i = 2; i <= (int)num; i++)
                {
                    sum *= i;
                }
                Console.WriteLine("{0}的阶乘为{1}", num, sum);
            }
            catch (FormatException)
            {
                Console.WriteLine("必须输入数字");
            }
            catch (Exception e)
            {
                Console.WriteLine(e.Message);
            }
            finally
            {
                Console.ReadKey();
            }
        }
    }
    
}