Have a string of "DateTimeTicks_Guid", use only CompareTo to generate find elements with a date range

I have a set of strings, the strings are in format: Ticks then an underscore than a Guid.

So for example: Ticks_Guid would be the string. The ticks are actually DateTime.MaxTicks - the ticks of 开发者_StackOverflow社区some date (aside: I do this to get the string to naturally show up in descending order).

Using only CompareTo is there a way to get the strings that are within a certain date range?

Since you say you have the strings in naturally descending order, I assume you have a fixed-width section for the ticks component of the string (otherwise the descending order bit won't work). The easiest comparison therefore would be to create two similarly formatted string; one for the tick value of the earlier date combined with an empty guid (all 0s) and another for the latter date combined with a guid that is all 0xFF, and then find the strings that sort between those in raw code-point order.

I'd just compare if the ticks are in between your dates to check in an if-statement:

ArrayList a = new ArrayList();
        string b = "345678_lalala";
        string c = "429817_lalelu";

        a.Add(b);
        a.Add(c);
        //date to check
        string begin = "298918";
        string end = "419812";


        ArrayList outputList = new ArrayList();
        foreach (string str in a)
        {
            if (str.CompareTo(begin) == 1 && str.CompareTo(end) == -1)
            {
                outputList.Add(str);
            }
        }