For Loop returning wrong output (18)

Question about the task

Sum of the digits of a three-digit number

Under discussion

package com.codegym.task.task01.task0132;

/*
Sum of the digits of a three-digit number

*/

    public class Solution {
        public static void main(String[] args) {
            System.out.println(sumDigitsInNumber(546));

        }

        public static int sumDigitsInNumber(int number) {
            int sum = 0;
            for (int i = number; i > 0; i /= 10){
                int remainder = number % 10;
                sum += remainder;
            } return sum;
        }
    }

Can anyone please tell me what i'm doing wrong here? My output is 18 instead of 15. I want to complete this using a for loop and not a while loop.

Write the code for sumDigitsInNumber(int number). The method takes a three-digit whole number. You need to calculate the sum of the digits of this number, and then return the result.

Consider this example:
The sumDigitsInNumber method is called with the argument 546.

Example output:
15

Requirements:

The program must not read data from the keyboard.
The sumDigitsInNumber(int) method must be public and static.
The sumDigitsInNumber method must return an int.
The sumDigitsInNumber method should not display anything.
The sumDigitsInNumber method must return the sum of all digits in the parameter number.

package com.codegym.task.task01.task0132; /* Sum of the digits of a three-digit number */ public class Solution { public static void main(String[] args) { System.out.println(sumDigitsInNumber(546)); } public static int sumDigitsInNumber(int number) { int sum = 0; while(number > 0) { sum = sum + number % 10; number = number /10; } return sum; } }

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Michael Brimage

Level 19 , Washington D.C., United States

11 February 2020, 14:19

I will try to help based on my current understanding (level 4 and without the use of loops). I broke the three digit number into ones, tens and hundreds. Step 1: using mod 10 (number % 10) returned the ones digit == number1. Step 2: divide number by ten (number /10) will yield a double digit number, which you should return the remainder of ( number2 % two-digit number). This will provide the tens number (the "4"). Step 3, divide by 100 to get the final digit. Step 4, return the sum. I know this is verbose, but I hope it helps.

Jack

Level 4 , Yerevan, Armenia

7 June 2020, 20:06

can you explain why we do

int sum = 0;
            while(number > 0)

and what is the % for

Shuy

Level 9 , Frankfurt, Germany

11 February 2020, 12:51

Its because on Line 17 youre using the variable number, which always stays 546, resulting in getting 3 times 6 as remainder (6+6+6 = 18). Just use i instead of number there.

Guadalupe Gagnon

Level 37 , Tampa, United States

11 February 2020, 16:34

i agree Either use i or change your for loop to:

for (; number > 0;  number /= 10){