java - control structure, repetition exercise: How to get the sum of the digits of a number? -

guys can please me answer exercise using loop without using string methods.

write program prompts user input integer , outputs both individual digits of number , sum of digits. example, program should output individual digits of 3456 3 4 5 6 , sum 18,and output individual digits of -2345 2 3 4 5 , sum 14.

this code:

package mypackage;  import java.util.*;  public class integer  {     public static void main(string args[])     {           scanner console = new scanner (system.in);        int input;        int sum = 0;        int num1 = 0;        int counter = 1;        string num = "";         system.out.print("enter number: ");        input = console.nextint();         if (input == (-input))                   {                 input = input * (-1);                num = string.valueof(input);                num1 = num.length();                system.out.print("the digits of " + input + " are: ");                 (int = 0; < num1; i++ )                {                   string var = num.substring(i,counter);                   int var1 = character.getnumericvalue(var.charat(0));                   system.out.print(var + " ");                   sum = sum + var1;                   counter++;                }                system.out.println();                system.out.println("the sum is: " + sum);           }          else                                 {                   num = string.valueof(input);                num1 = num.length();                system.out.print("the digits of " + input + " are: ");                 (int = 0; < num1; i++ )                {                    string var = num.substring(i,counter);                    int var1 = character.getnumericvalue(var.charat(0));                    system.out.print(var + " ");                    sum = sum + var1;                    counter++;                }                system.err.println();                system.out.println("the sum is: " + sum);           }   } } 

iterating digits from right left easy enough - keep dividing 10 , keeping remainder. since need print them left right, there don't seem constraint on memory usage, keep them in list, , print backwards:

int num = ...; // inputed user list<integer> digits = new linkedlist<>(); int sum = 0;  // extract digits , sum while (num != 0) {     int digit = num % 10;     digits.add (digit);     sum += digit;     num /= 10; }  // print backwards: system.out.print ("the digits are: "); (int = digits.size() - 1; >= 0; --i) {     system.out.print (digits.get(i) + " "); } system.out.println(); system.out.println("their sum is: " + sum);