Question

What is the regular expression for Date format dd\mm\yyyy? I am unable to find out regex for this format?

Answer 1

In my opinion, it’s best to verify the formatting using a regular expression, but verify the validity with code (Java, in your case). It would be absurdly verbose to try to check things like differing days per month and leap years with a regular expression.

I suggest parsing the date using a regex like ([0-9]{2})\\([0-9]{2})\\([0-9]{4}), then extract each piece (dd, mm, and yyyy, respectively), and try to create a java.util.Date object out of them.

Note the following:

• Dates are typically written with forward slashes (/) not backslashes (\),
• In Java strings, to write a backslash character in a regular expression, you will have to actually write \\\\ for two backslash (\\) characters. In java strings to write a backslash we need the escape character (which is again a \).