求助算法问题，在线等

Question

数组1 ＝ 606,629,631,609
数组2 ＝ 606,631,609
两个数组中比较，取出数组中不同的一项629,只要629
另外下面是我写的，请帮我看看，先谢谢了
 foreach (ListItem sItem in Chk_Selected.Items)
                        {
                            foreach (string strArr in lastSelectItem.TrimEnd(',').Split(','))
                            {
                                if (sItem.Value == strArr)
                                {
                                    break;
                                }
                                else
                                {
                                    sValue = sItem.Value;
                                }
                            }
                        }

Answer 1

理论上没什么问题，但是
1能确定是数组1中比数组2中多吗？
2能确定只有一项吗？就算这两条都成立 你的算法也不对，数组1中631和609交换以后结果就不正确了
  string returnvalue = "";
        bool biaozhi = false;
        foreach (ListItem sItem in Chk_Selected.Items)
        {
            foreach (string strArr in lastSelectItem.TrimEnd(',').Split(','))
            {
                if (sItem.Value == strArr)
                {
                    biaozhi = true;
                    break;
                }
            }
            if (!biaozhi)
            {
                returnvalue = sItem.Value;
                break;
            }
        }

Answer 2

把较短的那组内容放到LIST中，然后利用Contains方法判断另一组是否存在于LIST中，如果FLASE自然就是不同项了。

Answer 3

        List<string> listA = new List<string>();
        listA.Add("606");
        listA.Add("629");
        listA.Add("631");
        listA.Add("609");        List<string> listB = new List<string>();
        listB.Add("606");
        listB.Add("631");
        listB.Add("609");        foreach (string str in listB)
        {
            if (listA.Contains(str))
            {
                listA.Remove(str);
            }
        }        foreach (string str in listA)
        {
            Response.Write(str);
            Response.Write("<br/>");
        }

Answer 4

to :scjtswj 
谢谢啊！之前用了下面这种方法 bool flag = false;                        for (int i = 0; i < Chk_Selected.Items.Count; i++)
                        {
                            for (int j = 0; j < strExis.Length; j++)
                            {
                                if (strExis[j].Trim() == Chk_Selected.Items[i].Value.Trim())
                                {
                                    break;
                                }
                                else
                                {
                                    if (j + 1 == strExis.Length)//找完所有第二个数组，没找到相同的
                                    {
                                        sValue = Chk_Selected.Items[i].Value.Trim();
                                        flag = true;
                                        break;//没找到相同的，跳出本循环
                                    }
                                    continue;
                                }                            }
                            if (flag)
                            {
                                break;//没找到相同的，跳出循环
                            }
                        }