java - How to check if a string matches a specific format?

Question

I want to check if a string matches the following format:

"00-00"

There should be no whitespace in the String, only 2 numbers before the dash and 2 numbers after the dash.

What's the best way to do this?

Answer 1

You can use matches():

str.matches("\d{2}-\d{2}")

If you're going to be doing this sort of validation a lot, consider pre-compiling the regex:

Pattern p = Pattern.compile("\d{2}-\d{2}");  // use a better name, though

You can then use p.matcher(str).matches(). See the Pattern class for more details.