converting a string to a date in C#

Question

I was wondering how I would convert a string of four to six digits to a date in C#?

111110 would be 11 11 10

111 10 would be 11 1 10

1 1 10 would be 1 1 10

The pattern being mmddyy mmd yy m d yy and the spaces are either ' ' or '\0' (the input I am given is not very clean)

This what I have so far and it works for all above cases, its just not very pretty: Is there a more efficient solution to the above cases?

//Converts the given input string into a valid Date
private DateTime convertToDateFromString(string dateString)
{
  int length = dateString.Length;
  int month = 1;
  int day = 1;
  int year = 1;
  bool gotMonth = false;
  bool gotDay = false;
  bool gotYear = false;
  char c = ' ';
  char peek = ' ';
  string buffer = "";
  DateTime bufferDate;
  int count = 0;

  try
  {
    //loop character by character through the string
    for (int i = 0; i < dateString.Length; i++)
    {
      c = dateString[i];
      if ((i + 1) < dateString.Length)
        peek = dateString[i + 1];
      else
        peek = '\0';

      if (c != ' ' && c != '\0')
      {
        buffer += c;
        count++;
        //Check if the month is done
        if ((peek == ' ' || peek == '\0' || count == 2) && gotMonth == false)
        {
          count = 0;
          gotMonth = true;
          month = int.Parse(buffer);
          buffer = null;
        }
        //Check if the day is done
        else if ((peek == ' ' || peek == '\0' || count == 2) && gotDay == false && gotMonth == true)
        {
          count = 0;
          gotDay = true;
          day = int.Parse(buffer);
          buffer = null;
        }
        //Check if the year is done
        else if ((peek == ' ' || peek == '\0' || count == 2) && gotYear == false && gotMonth == true && gotDay == true)
        {
          count = 0;
          gotYear = true;
          year = int.Parse(buffer);
          buffer = null;

          if (year >= 80 && year <= 99)
            year += 1900;
          else if (year >= 0 && year <= 79)
            year += 2000;
        }
      }
    }
    bufferDate = new DateTime(year, month, day);
  }
  catch (System.Exception ex)
  {
    bufferDate = new DateTime(1, 1, 1);
  }
  return bufferDate;
}

This is what happens when you don't do enough research on available functions and try to do things from scratch... — NexAddo
– NexAddo, Commented Nov 10, 2011 at 22:12
Is it me or did you just rewrite a new question for one that has been closed one hour before? stackoverflow.com/questions/8086209/… — Otiel
– Otiel, Commented Nov 10, 2011 at 23:38

Henk Holterman · Accepted Answer · 2011-11-10 22:13:23Z

3

You discriminator here is the number of spaces. First get that:

string source = "....";    
int spaceCount = source.Count(c => c == ' ');

Then create formatstrings for the expected range 0..2 . You can use the strings from the question except that you have to use M for the months:

var formats = new string[] { "MMddyy", "MMd yy", "M d yy" };

and then you can get your date :

DateTime r = DateTime.ParseExact(source, formats[spaceCount], null);

Add validations as required.

edited Nov 10, 2011 at 22:13

answered Nov 10, 2011 at 21:55

Henk Holterman

276k33 gold badges353 silver badges540 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

McKay · Accepted Answer · 2011-11-10 21:46:15Z

3

Try using

DateTime.TryParseExact(dateString, new string[] { "MMddyy", "MMd yy", "M d yy" }, CultureInfo.CurrentCulture, DateTimeStyles.AssumeLocal, out result);

if you need to you can

dateString = dateString.Replace('\0', ' ');

before you begin

answered Nov 10, 2011 at 21:46

McKay

12.7k7 gold badges58 silver badges81 bronze badges

1 Comment

NexAddo Over a year ago

That's a much more efficient solution. Thanks!

Oded · Accepted Answer · 2011-11-10 21:55:39Z

3

You should use one of the many Parse methods defined on DateTime.

These will take the string, an optional format string (describing the format of the datetime string) and an optional culture.

Take a look at Parse, ParseExact, TryParse and TryParseExact, some of which will take a string[] of the formats to try.

Additionally, here available string formats - standard and custom date and time format strings.

edited Nov 10, 2011 at 21:55

answered Nov 10, 2011 at 21:44

Oded

501k102 gold badges900 silver badges1k bronze badges

6 Comments

NexAddo Over a year ago

Is there a list of acceptable string formats for DateTime.Parse?

Oded Over a year ago

@NexAddo - Yes, there is. Answer amended.

McKay Over a year ago

The problem is that he has many format strings he needs to use.

Oded Over a year ago

@McKay - some the parse methods take a string[] of the different formats to try. Which you seem to know about from your answer.

McKay Over a year ago

@Oded The ParseExact methods do, not the Parse methods. (hence my answer that actually does take an array of formats)

|

Collectives™ on Stack Overflow

converting a string to a date in C#

3 Answers 3

Comments

1 Comment

6 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

Comments

1 Comment

6 Comments

Your Answer

Sign up or log in

Post as a guest

Related