Java Program to remove special characters and print sum of the unique numerical characters in the given string

Question:

Program to remove special characters and print sum of print sum of the unique numerical characters in the given string

Input: 123%#$.257
Output: Sum: 18

Program:

import java.io.*;

public class LetUsCodeinC{
     public static void main(String[ ] args){
           String inpStr = "123%#$.257";
           //Removing special characters from the given string
           inpStr = inpStr.replaceAll("[^0-9]","");
           String resStr = "";
           int sum = 0;
           //Removing duplicates from the resStr String
           for(int i = 0; inpStr.length( ); i++){
                if(!resStr.contains(String.valueOf(inpStr.charAt(i)))){
                     resStr += String.valueOf(inpStr.charAt(i));
                }
           }
           //Sum of all the numeric characters of resStr.
           for(int i = 0; resStr.length( ); i++){
                sum += Integer.parseInt(resStr.charAt(i) + "");
           }
           System.out.println("Sum: " + sum);
     }
}

Output:

Sum: 18

Explanation:

First we need to divide this program into 3 modules.
    1. Removing special characters from the given string.
    2. Removing duplicates from the resultant string.
    3. Sum of all the resultant numeric characters of string.