Regex for Delimeter

Question

I am trying to write a regex for delimiters “(“, “)”, “,”. I tried to write a regex but it is not the correct for the delimeters.

Let's say the input is mult(3,add(2,subs(4,3))). The output with my delimeter regex is: 3,add(2,subs(4,3.

public class Practice {

    private static final String DELIMETER = "\\((.*?)\\)";

    public static void main(String[] args) {
        Scanner reader = new Scanner(System.in);
        String arg = reader.next();
        Pattern p = Pattern.compile(DELIMETER);
        Matcher m = p.matcher(arg);
        while (m.find()) {
            System.out.println(m.group(1));
        }
    }
}

What is the correct regex to get string between the delimeters?

It seems to me that you want the match to be greedy, not reluctant. What happens if you remove the `?` from the middle of the expression? — Dawood ibn Kareem, Dec 11 '17 at 17:39

score 0 · Answer 1 · answered Dec 11 '17 at 17:37

In general, you cannot use a regex to match anything which can nest recursively. However, if you removed the ? from your regex, it would match from the first ( to the last ), which might be good enough, depending on what you expect the input to look like.

Regex for Delimeter

1 Answers1