/* Given a string, return the sum of the digits 0-9 that appear in the * string, ignoring all other characters. Return 0 if there are no digits in * the string. */ public int sumDigits(String str) { int sum = 0; for(int i = 0; i < str.length(); i++) { if(Character.isDigit(str.charAt(i))) sum = sum + str.charAt(i) - '0'; } return sum; }