Find count of digits in string variable

A cleaner solution using Regular Expressions:

// matches all non-digits, replaces it with "" and returns the length.
s.replaceAll("\\D", "").length()

String s = "2485083572085748";
int count = 0;
for (int i = 0, len = s.length(); i < len; i++) {
    if (Character.isDigit(s.charAt(i))) {
        count++;
    }
}

Just to refresh this thread with stream option of counting digits in a string:

"2485083572085748".chars()
                  .filter(Character::isDigit)
                  .count();