Extract Numbers in Java

1import java.util.Scanner;
2
3public class Main {
4    public static void main(String[] args) {
5        Scanner sc = new Scanner(System.in);
6        System.out.print("Enter a string: ");
7        String s = sc.nextLine();
8
9        StringBuilder digits = new StringBuilder();
10        for (int i = 0; i < s.length(); i++) {
11            if (Character.isDigit(s.charAt(i))) {
12                digits.append(s.charAt(i));
13            }
14        }
15        System.out.println("Digits: " + digits.toString());
16        sc.close();
17    }
18}