Removing string before open parenthesis using regular expression

Question

I have an expression Nvl(cost,Sum(cost1)) i need to remove string before paranthesis ie NVl and Sum in this case

        String functions=externalFormat.replaceAll("\\([^\\(]*\\)", "");

Input Nvl(cost,Sum(Cost1) Output cost,cost1

Answer 1

If you can't use capture groups (ie, if you CAN use capture groups, (\\w*?)\\( will capture the text you need to replace in the first group)

You could use a positive look-ahead to only capture word characters (letter or number) that appear before an open bracket:

\w*(?=\()

You could even add optional white space characters in case of things like: Nvl1 (cost,Sum (cost1)) by including them before the look-ahead: -

\w*\s*(?=\()

Hope this helps solve your problem.

Answer 2

Check below code :

public static void main(String[] args) {
        String externalFormat="Nvl(cost,Sum(Cost1)";
        String functions=externalFormat.replaceAll("\\w+\\(|\\)", "");
        System.out.println(functions.toLowerCase());

    }