CODEWITHSUNDEEP
javaregex
techtinkerer
techtinkerer

Reputation: 1300

Pattern matching with Java regex

My server dev gave me a regex that he says is the requirement for user name. It is @"^\w+([\s-]\w+)*$"

I need help figuring out right Java expression for this. It is confusing since I need to put some escape characters to make compiler happy.

I am trying this. Please let me know if this is right :

Pattern p = Pattern.compile("^\\w+([\\s-]\\w+)*\\$", Pattern.CASE_INSENSITIVE);

   Matcher m = p.matcher(username);

   if ((username.length() < 3 ) || (m.find())) {
      log ("Invalid pattern"); 
      return false;
   }

Is this correct ?

Upvotes: 3

Views: 96

Answers (2)

Raman Sahasi
Raman Sahasi

Reputation: 31841

In your regex

^\\w+([\\s-]\\w+)*\\$
                    ^

You don't have to escape this $. It is there to indicate End Of Line.

so the correct Regex would be:

^\\w+([\\s-]\\w+)*$

N.B.: However, you have to make sure that this $ sign doesn't represent $ literally. In that case you'd have to escape it, but I anticipate in that case it would be escaped in your source RegEx as well.

Upvotes: 2

Wagner DosAnjos
Wagner DosAnjos

Reputation: 6374

The correct pattern is "^\\w+([\\s-]\\w+)*$".

$ denotes the end of the string, if you use \\$ it will force the string to have the char $ and that's not the intent.

Upvotes: 3

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