c# 一个算质数的小程序，可以找出一定范围内的质数，可以求质数的个数，与打印所有质数。

也许以后能用到，存档先。

using System;
using System.Collections.Generic;
using System.Text;
using System.Collections;

namespace Date1223_3
...{
    class PrimeNum
    ...{
        public static void Main(String[] args)
        ...{
            bool div = false;
            ArrayList list = new ArrayList();

            Console.WriteLine("输入你想要算质数的范围：");
            int range = Int32.Parse(Console.ReadLine());
            Console.WriteLine("你想要算出{0}以内的质数,点Enter计算",range);
            Console.ReadLine();

            for (int i = 2; i < range+1; i++)
            ...{
                div = false;
                for (int j = 2; j < i; j++)
                ...{
                    if (i % j == 0)
                    ...{
                        div = true;
                        break;
                    }  
 

              }
                if (!div)
                ...{
                    
                    list.Add(i);
                    
                }
                
            }

            Console.WriteLine("一百内的质数个数为：");
            Console.WriteLine(list.Count);
            Console.WriteLine("具体的质数如下：");
            for (int i = 0; i < list.Count; i++)
            ...{
                Console.WriteLine(list[i].ToString());
            }
            Console.ReadLine();
        }
    }
}