String Format In C# / windows

Question

I have a component in my c# application that provide strings like these:

"2004/1/11"

"2015/12/10"

"1998/1/2"

But i want to change them to these formats:

"2004/01/11"

"2015/12/10"

"1998/01/02"

Any idea?

Answer 1

It seems that the strings in the question are actually dates, in that case DateTime class is what you're looking for:

  String source = "2015/12/10";
  String result = DateTime
   .ParseExact(source, "yyyy/M/d", CultureInfo.InvariantCulture)
   .ToString("yyyy/MM/dd", CultureInfo.InvariantCulture);

In case the strings are not dates (say, some weird codes which look like dates) and you want just insert zeroes:

  String source = "2015/12/10"; 
  String result = Regex
    .Replace(source, "(?<=/)[0-9](?![0-9])", match => "0" + match.Value);

Answer 2

Try :

   string InputStr = "2004/1/11";
   String OutputStr = String.Format("{0:yyyy/MM/dd}", Convert.ToDateTime(InputStr));

Answer 3

If you do not want to convert the strings to dates and back, you could use the Regex.Replace-method. The code could look a little something like this:

myString = Regex.Replace(myString,@"[^\d](\d)(?=(/|$))","/0$1");

EDIT: Corrected the pattern.

Answer 4

This might help you out with your question: https://msdn.microsoft.com/en-us/library/8kb3ddd4(v=vs.110).aspx

Maybe a timeformat setting will solve your problem.

Answer 5

its date so you can convert it this way

string str = "2004/1/11";
DateTime dt = DateTime.ParseExact(str, "yyyy/M/dd", CultureInfo.InvariantCulture);
string newstr = dt.ToString("yyyy/MM/dd", CultureInfo.InvariantCulture)