Regular expression for date : DDMMMYYY

[snahil]

Hi,

I am using a regular expression to validate a date format. The Date format which the user would enter is : DDMMMYYYY ( like 10OCT2001)

I am using the following regular expression :

^(0[1-9]|[12][0-9]|3[01])(JAN|FEB|MAR|APR|MAY|JUN|JUL|AUG|SEP|OCT|NOV|DEC| jan|feb|mar|apr|may|jun|jul|aug|sep|oct|nov|dec)(1 9|20)\d\d$

But this fails, if the user gives a combination of upper and lower case in months
( something like 10Oct2009 )...so could you please tell me how to change the above regex so that it ignores the case in the month field ?

[tlhintoq]

I'm not good at RegEx but I can make a suggestion...
Take the text entered by the user and fix it before you check it.

string usersubmission = Textbox1.Text.ToUpper();
// Go check against RegEx

[Plater]

For this specific example, couldn't you use the DateTime object's ParseExact() or TryParseExact() functions? It takes in a parameter of like "DDMMMYYYY" as a pattern.

For example:

 
DateTime myDT = DateTime.MinValue;
IFormatProvider culture = System.Globalization.CultureInfo.CurrentCulture;
bool result=DateTime.TryParseExact(myTextbox.Text, "DDMMMYYYY", culture, System.Globalization.DateTimeStyles.AssumeLocal, out myDT);
 
 

[GaryTexmo]

I did a bit of googling, you can set an option to have your RegEx ignore case. Here's the MSDN page on it...

http://msdn.microsoft.com/en-us/libr...exoptions.aspx

From that page...

Regex rxInsensitive = new Regex(@"\b(?<word>\w+)\s+(\k<word>)\b", RegexOptions.Compiled | RegexOptions.IgnoreCase);
 

Hopefully that helps! :)