Extract Integer Part in String

Question

What is the best way to extract the integer part of a string like

Hello123

How do you get the 123 part. You can sort of hack it using Java\

Answer 1

Assuming you want a trailing digit, this would work:

import java.util.regex.*;

public class Example {


    public static void main(String[] args) {
        Pattern regex = Pattern.compile("\\D*(\\d*)");
        String input = "Hello123";
        Matcher matcher = regex.matcher(input);

        if (matcher.matches() && matcher.groupCount() == 1) {
            String digitStr = matcher.group(1);
            Integer digit = Integer.parseInt(digitStr);
            System.out.println(digit);            
        }

        System.out.println("done.");
    }
}