Java Regular Expression: match any number of digits in round brackets if the closing bracket is the last char in the String

Question

I need some help to save my day (or my night). I would like to match:

1. Any number of digits
2. Enclosed by round brackets "()" [The brackets contain nothing else than digits]
3. If the closing bracket ")" is the last character in the String.

Here's the code I have come up with:

// this how the text looks, the part I want to match are the digits in the brackets at the end of it
    String text = "Some text 45 Some text, text and text (1234)";  
    String regex = "[no idea how to express this.....]"; // this is where the regex should be
            Pattern regPat = Pattern.compile(regex);
            Matcher matcher = regPat.matcher(text);

            String matchedText = "";

            if (matcher.find()) {
                matchedText = matcher.group();
            }

Please help me out with the magic expression I have only managed to match any number of digits, but not if they are enclosed in brackets and are at the end of the line...

Thanks!

Answer 1

You can try this regex:

String regex = "\\(\\d+\\)$";

Answer 2

If you need to extract just the digits, you can use this regex:

String regex = "\\((\\d+)\\)$";

and get the value of matcher.group(1). (Explanation: The ( and ) characters preceded by backslashes match the round brackets literally; the ( and ) characters not preceded by backslashes tell the matcher that the part inside, i.e. just the digits, form a capture group, and the part matching the group can be obtained by matcher.group(1), since this is the first, and only, capture group in the regex.)

Answer 3

This is the required regex for your condition

\\(\\d+\\)$