Array Sequence TimeStamp Validation

Question

I am getting an error below that the string is not a valid datetime format. Can someone help below.

using System;

using System.Linq;

using System.Text.RegularExpressions;

class Test

{

static void Main()

{

string[] ArrayElement = new string[6];

ArrayElement[0]= "1:05:00 PM 06/25/2013 On True";

ArrayElement[1]= "1:10:00 PM 06/25/2013 Off True";

ArrayElement[2]= "1:15:00 PM 06/25/2013 On True";

ArrayElement[3]= "1:20:00 PM 06/25/2013 Off True";

ArrayElement[4]= "1:25:00 PM 06/25/2013 On True";

ArrayElement[5]= "1:30:00 PM 06/25/2013 Off True";

Console.WriteLine(Validate(ArrayElement)); // True

ArrayElement[2]= "1:15:00 PM 05/25/2013 On True";

Console.WriteLine(Validate(ArrayElement)); // False

Console.ReadKey();

}

static bool Validate(string[] state)

{

string f = "h:mm:ss tt MM/dd/yyyy";

// extract time stamps and make sure they're in sequence

DateTime[] stamps = state

.Select(s => DateTime.ParseExact(s.Substring(0, s.LastIndexOf(" ")), f, null)).ToArray();

for(int i = 1; i < stamps.Length; i++)

{

if(stamps[i] < stamps[i-1]) return false;

}

// extract On/Off's and validate them

state = state.Select(s => s.Substring(s.IndexOf("O"))).ToArray();

string text = String.Join("", state);

string regExp = "^(OnOff)+$";

return Regex.IsMatch(text, regExp);

}

David Smith · Answer

I found out why the MM/dd/yyyy was not working. I look at the input string carefully and the input was incorrect according to the format. 9/25/2013 Incorrect 09/25/2013 correct I am enduring the format is using the MM/dd/yyyy by doing this below. sb.Append(c.ColorTimeTag.ToString(MM/dd/yyyy HH:mm:ss tt)); Thanks vuples.

Vulpes · Answer

Well M/d/yyyy would validate a date such as 8/1/2013 and also 08/01/2013. So if either of these are possible I'd stick with this.

David Smith · Answer

Can I go wrong using this format M/d/yyyy

David Smith · Answer

Can I go wrong using this format M/d/yyyy

David Smith · Answer

I prefer to use MM/dd/yyyy also. I am not for sure why this didn't work at all. However this work M/d/yyyy I am very confuse why this work and this did not work MM/dd/yyyy.

Vulpes · Answer

The difference is that you always have to use 2 digits to express the month or day with 'MM/dd/yyyy'. So today would be 22/08/2013. With 'M/d/yyyy' you use one digit if it's a single digit month or day or two digits otherwise. So today in this format would be 22/8/2013. Personally I prefer to use the 'MM/dd/yyyy' format because this always has the same length. However if the data is being supplied externally you may not have a choice.

David Smith · Answer

Vuples this format work below. private const string TIMESTAMP_FORMAT = M/d/yyyy HH:mm:ss tt; what is the difference between M/d/yyyy and MM/ds/yyyy

Vulpes · Answer

Another thing I've noticed is that we're expecting the date to be in this format: MM/dd/yyyy However I've noticed one or two dates in your posts which only had one digit in the day. Maybe we should be using M/d/yyyy instead?

David Smith · Answer

That was a mistake. I still get the error when using Thr ArrayElement string arrat

Vulpes · Answer

I don't know what 'history' is but you should be comparing the original array with the same array after it's been ordered to see whether they're the same or not: if (!ArrayElement.SequenceEqual(orderedState)) { return false; }

David Smith · Answer

Well thats not it. The substring is working. But however I am still getting the error. I am not for sure what it is. string [] ArrayElement = state.Select(s => s.Substring(0 s.IndexOf(O) - 1)).ToArray(); // extract time stamps and make sure they're in sequence var orderedState = ArrayElement.OrderBy(s => DateTime.ParseExact(s TIMESTAMP_FORMAT null)); if (!history.SequenceEqual(orderedState)) { return false; }

David Smith · Answer

Vuples so do i need to make sure that AM/PM is the string like below. string f = MM/dd/yyyy h:mm:ss tt ; 8/21/2013 10:05:09 AM On True However I dont think the substring is working correctly embedded in the ParseDate function below. I the error is complaining about the entire string 8/21/2013 10:05:09 AM On True. When you think ON and TRUE  is an invalid datetime format if that make sense. var orderedState = state.OrderBy(s => DateTime.ParseExact(s.Substring(0 s.IndexOf(O) - 1) TIMESTAMP_FORMAT null)); I get an error on this line. if (!history.SequenceEqual(orderedState)) { return false; }

Vulpes · Answer

Also I've just noticed that you've got the date before the time rather than the other way around. The strings need to be in the exact format specified for this to work.

Vulpes · Answer

If you don't have AM or PM in the string then that's definitely the problem as you're using DateTime.ParseExact.

David Smith · Answer

I am still getting the same error string was not recognized as a valid datetime. This is my exact code below. Also this is my exact string below when I look in the debugger. 8/21/2013 10:05:09 On True I notice that I dont have the AM/PM in the string. That could be the problem also private const string TIMESTAMP_FORMAT = h:mm:ss tt MM/dd/yyyy; private static bool Validate(string[] state) { var orderedState = state.OrderBy(s => DateTime.ParseExact(s.Substring(0 s.IndexOf(O) - 1) TIMESTAMP_FORMAT null)); I get an error on this line. if (!history.SequenceEqual(orderedState)) { return false; } else { return true; } }

Vulpes · Answer

I'm not sure that any of the standard Exception classes really fit the bill. I suppose ArgumentException is the closest as there's something wrong with the array that's passed in: throw new ArgumentException(Array elements are not in order);

David Smith · Answer

What exception class can I throw instead of returning.

Vulpes · Answer

I've just tried it again to make absolutely sure but the code is working fine as posted. The AM/PM desigmator is catered for in the format string you provided yourself: string f = h:mm:ss tt MM/dd/yyyy; I suppose you could replace this part of the code: DateTime[] stamps = state .Select(s => DateTime.ParseExact(s.Substring(0 s.LastIndexOf( )) f null)).ToArray(); for(int i = 1; i { if(stamps[i] } with this: var orderedState = state.OrderBy(s => DateTime.ParseExact(s.Substring(0 s.IndexOf (O) - 1) f null)); if(!state.SequenceEqual(orderedState)) return false;

David Smith · Answer

string test = ArrayElement[0].Substring(0 ArrayElement[0].IndexOf(O) - 1); This logic works below which is for testing purposes. string f = h:mm:ss tt MM/dd/yyyy; DateTime dt = DateTime.ParseExact(test f null); Console.WriteLine(test); This logic is not working at all below I am getting string is not in a valid datetime format. DateTime[] timestamps = ArrayElement.Select(s => DateTime.ParseExact(s.Substring(0 s.IndexOf(O) - 1) f null)).ToArray();

David Smith · Answer

Vuples I still get the error String was not recognized as a valid DateTime.

David Smith · Answer

Vuples your logic is not accounting for the AM and PM in the timestamp

David Smith · Answer

Vuples I havent tested it yet. But is there another way to use the without using the for loop.

Vulpes · Answer

Try this: using System; using System.Linq; using System.Text.RegularExpressions; class Test { static void Main() { string[] ArrayElement = new string[6]; ArrayElement[0]= 1:05:00 PM 06/25/2013 On True; ArrayElement[1]= 1:10:00 PM 06/25/2013 Off True; ArrayElement[2]= 1:15:00 PM 06/25/2013 On True; ArrayElement[3]= 1:20:00 PM 06/25/2013 Off True; ArrayElement[4]= 1:25:00 PM 06/25/2013 On True; ArrayElement[5]= 1:30:00 PM 06/25/2013 Off True; Console.WriteLine(Validate(ArrayElement)); // True ArrayElement[2]= 1:15:00 PM 05/25/2013 On True; Console.WriteLine(Validate(ArrayElement)); // False Console.ReadKey(); } static bool Validate(string[] state) { string f = h:mm:ss tt MM/dd/yyyy; // extract time stamps and make sure they're in sequence DateTime[] stamps = state .Select(s => DateTime.ParseExact(s.Substring(0 s.IndexOf(O) - 1 ) f null)).ToArray(); for(int i = 1; i { if(stamps[i] { return false; } } // extract On/Off's and validate them state = state.Select(s => Regex.Match(s (On|Off)).Value ).ToArray(); string text = String.Join( state); string regExp = ^(OnOff)+$; return Regex.IsMatch(text regExp); } } The output should be: True False