Question

Write a Java program to return the sum of the digits present in the given string. If there is no digit, the sum return is 0.

Answer 1

import java.util.Scanner;

public class SumDigitsInString {

    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        System.out.print("Enter a string: "); // ask user for a string
        String s = in.nextLine(); // read string from user
        int sum = 0; // create sum variable and initialize it with 0
        for (int i = 0; i < s.length(); i++) {  // go through all characters of string
            if (Character.isDigit(s.charAt(i))) { // if character is a digit
                sum += s.charAt(i) - '0';   // then add that digit to sum
            }
        }
        System.out.println(sum);    // finally print the calculated sum
    }
}