java - SumDigits using Parameter -

okay, created digitssum application. class digitssum , contain static method called sumdigits(i done this). ( didn't part) names must match these including capitalization, sumdigits method should take single parameter, integer, , return sum of digits in integer, sumdigits method should not print anything, , should return answer using return statement. can use main method test sumdigits method, , printing should happen there. know whether if did fine or no..also method return should if entered number, suppose 345, output should 3+4+5=12 --> 1+2 = 3. doing wrong here? in advanced!

  import java.util.scanner;        public class sumdigits {              public static double sumdigits (int a){                 int sum;                 int t= a%10;                 sum= t+t;                 = a/10;                 return (sum);                }              public static void main (string [] args){                  double sumdigit;                     int integer;                  scanner in = new scanner(system.in);                 system.out.print("enter positive integer: ");                    integer = in.nextint();                  sumdigit = sumdigits(integer);                 system.out.println ("the sum of digit is:" +sumdigit);              }         } 

i believe you're missing few things:

• you should close streams , external resource in general. id est: closing scanner before leaving main method
• as has been pointed out in comments, should use recursive method implement sumdigits, because reflects actual behavior you're trying implement.

your code this:

public class main {     public static int sumdigits(final int a) {         int sum = 0;         int b = a;         {             sum += b % 10;             b = b / 10;         } while (b > 0);          if (sum >= 10) {             return sumdigits(sum);         }          return sum;     }      public static void main(final string[] args) {          double sumdigit;         int integer;          try (final scanner in = new scanner(system.in)) {             system.out.print("enter positive integer: ");             integer = in.nextint();              sumdigit = sumdigits(integer);             system.out.println("the sum of digit is: " + sumdigit);         }      } } 

what did here in recursive method can decomposed in 2 parts:

1. you calculate sum of digits of given number (done do/while loop)
2. if sum greater or equals 10, need return recursive application of sumdigits on value... otherwise, return sum.

note didn't change sumdigits method main one, closes scanner using try-with-resource syntax.