Question

I’m not able to get this to match correctly. It only prints “[help]” but I want it to match the characters inside the brackets.

want:

[help]
help

code:

        Pattern p = Pattern.compile("\\[(\\w+)\\]");
        Matcher m = p.matcher("[help]");
        m.find();


        for (int i=0;i<m.groupCount(); i++) {
            System.out.println(m.group(i));
        }

Answer 1

You need to check for <= for the groupCount. Like so:

for (int i = 0; i <= m.groupCount(); i++) {

From the Matcher Javadoc:

Any non-negative integer smaller than or equal to the value returned by this method is guaranteed to be a valid group index for this matcher.