Regex for Date problem

Question

I have string for example: 06.07.2010 (tor.)

I would like to extract only 06.07.2010 using a regex, but the following is not working correctly:

^([0-9]{1,2}).([0-9]{1,2}).([0-9]{4,4})$
^([1-9]|0[1-9]|[12][0-9]|3[01])[- /.]([1-9]|0[1-9]|1[012])[- /.][0-9]{4}$

Can someone tell me what is wrong here?

Answer 1

It's the $ at the end. It means there can't be any characters after the year digits - in other words, the RE has to match the entire string.

You probably want this instead:

^([0-9]{1,2}).([0-9]{1,2}).([0-9]{4,4})

Answer 2

Maybe there's more going on than what you say or the incoming string can be more complex, but why not just use String.Split? It's much more clear IMO.

string dateAndStuff = "06.07.2010 (tor)";
string[] parts = dateAndStuff.Split(' ');

if(parts.Length > 0)
{
  string date = parts[0];
  if(!string.IsNullOrEmpty(date)) //use date
}

Answer 3

The problem is that you are specifying that the end of the string ($) should follow immediately after the year. If you remove that condition, you will be able to get the date from the string. Also you are catching the components separately, so you won't get the date as a single string. Also, you need to escape the periods if you want them to match only periods, otherwise they will match any character:

^([0-9]{1,2}\.[0-9]{1,2}\.[0-9]{4,4})

or simply:

^(\d{1,2}\.\d{1,2}\.\d{4})