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c#stringdatetimedatetime-parsing
Sperick
Sperick

Reputation: 2761

Create DateTime object from various strings

I have a string that is in the format of a date. I want to convert it to a DateTime object. However I am not certain of the format of the string.

Are there any methods that I can use so that it will work on following inputs?

"12/31/2015", "31/12/2015", "2015-12-31"

Upvotes: 2

Views: 1046

Answers (4)

Mohamad Shiralizadeh
Mohamad Shiralizadeh

Reputation: 8765

you can use DateTime.Parse. try this code:

// Define cultures to be used to parse dates.
      CultureInfo[] cultures = {CultureInfo.CreateSpecificCulture("en-US"), 
                                CultureInfo.CreateSpecificCulture("fr-FR"), 
                                CultureInfo.CreateSpecificCulture("de-DE")};
      // Define string representations of a date to be parsed. 
      string[] dateStrings = {"01/10/2009 7:34 PM", 
                              "10.01.2009 19:34", 
                              "10-1-2009 19:34" };
      // Parse dates using each culture. 
      foreach (CultureInfo culture in cultures)
      {
         DateTime dateValue;
         Console.WriteLine("Attempted conversions using {0} culture.", 
                           culture.Name);
         foreach (string dateString in dateStrings)
         {
            try {
               dateValue = DateTime.Parse(dateString, culture);
               Console.WriteLine("   Converted '{0}' to {1}.",
                                 dateString, dateValue.ToString("f", culture));
            }
            catch (FormatException) {
               Console.WriteLine("   Unable to convert '{0}' for culture {1}.", 
                                 dateString, culture.Name);
            }
         }
         Console.WriteLine();

Source

Upvotes: 0

Soner Gönül
Soner Gönül

Reputation: 98750

DateTime.TryParseExact method has an overload which takes your formats as a string array.

string s = "";
DateTime dt;
var array = new[] {"MM/dd/yyyy", "dd/MM/yyyy", "yyyy-MM-dd"};
if(DateTime.TryParseExact(s, array, CultureInfo.InvariantCulture,
                          DateTimeStyles.None, out dt))
{
    //
}

I used InvariantCulture as a IFormatProvider because / format specifier has a special meaning of replace me with current culture or supplied culture date separator. That means, if you use CurrentCulture and it doesn't have / as a DateSeparator, your parsing will fail even if your string and format exactly matches.

But remember

This way is okey for your examples.

But string like 01/02/2015 is a problem because this method can't know that this is 1 February 2015 or 2 January 2015. In such a case, this method parse your string with first successfully matched format.

However I am not certain of the format of the string.

If you want to full successfully parse for your all examples, you have to know their exact formats.

Upvotes: 4

Anthony Faull
Anthony Faull

Reputation: 17957

You can use TryParseExact with a list of expected formats.

string[] formats = { "MM/dd/yyyy", "dd/MM/yyyy", "yyyy-MM-dd" };
DateTime outputDate;
DateTime.TryParseExact(inputText, formats, 
    CultureInfo.InvariantCulture, DateTimeStyles.None, out outputDate)

Upvotes: 4

Alex Zhukovskiy
Alex Zhukovskiy

Reputation: 10015

you can use list of allowed cultures:

        var list = new List<string> {"12/31/2015", "31/12/2015", "2015-12-31"};
        var allowedCultures = CultureInfo.GetCultures(CultureTypes.AllCultures);

        foreach (string s in list)
        {
            DateTime dt;
            foreach (CultureInfo culture in allowedCultures)
            {
                if (DateTime.TryParse(s, culture, DateTimeStyles.None, out dt))
                {
                    Console.WriteLine("{0} - {1}", culture.DisplayName, dt.ToShortDateString());
                    break;
                }
            }
        }

Upvotes: 0

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