toUpperCase(), replaceAll(), split(), Integer.praseInt()
class Solution {
public int solution(String my_string) {
int answer = 0;
String str = my_string.toUpperCase().replaceAll("[A-Z]", "");
String[] arr = str.split("");
for(int i = 0; i < arr.length; i++) {
answer += Integer.parseInt(arr[i]);
}
return answer;
}
}