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Java Exercises: Check whether a number is a Harshad Number or not

Java Numbers: Exercise-12 with Solution

Write a Java program to check whether a number is a Harshad Number or not.

In recreational mathematics, a harshad number in a given number base, is an integer that is divisible by the sum of its digits when written in that base.
Example: Number 200 is a Harshad Number because the sum of digits 2 and 0 and 0 is 2(2+0+0) and 200 is divisible by 2. Number 171 is a Harshad Number because the sum of digits 1 and 7 and 1 is 9(1+7+1) and 171 is divisible by 9.

Test Data
Input a number : 353

Pictorial Presentation:

Java: Check whether a number is a Harshad Number or not.

Sample Solution:

Java Code:

import java.util.Scanner;
public class Example12 {

     public static void main(String args[])
    {
        Scanner sc = new Scanner(System.in);
         
        System.out.print("Input a number : ");
        int num = sc.nextInt();
        int x = num, y, sum = 0;
         
       while(x>0)
        {
            y = x%10;
            sum = sum + y;
            x = x/10;
        }
         
        if(num%sum == 0)
            System.out.println(num+" is a Harshad Number.");
        else
            System.out.println(num+" is not a Harshad Number.");      
    }
}

Sample Output:

Input a number : 353                                                                                          
353 is not a Harshad Number.

Flowchart:

Flowchart: Check whether a number is a Harshad Number or not

Java Code Editor:

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Array vs ArrayLists:

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Ref: https://bit.ly/3o8L2KH