Check if a large number is divisible by 3 or not in java

If the sum of the digits of a number is divisible by 3, then the number is divisible by 3.

Some examples of numbers divisible by 3 are as follows.

• The number 85203 is divisible by 3 because the sum of its digits (8 + 5 + 2 + 0 + 3 = 18) is divisible by 3.
• The number 79154 is not divisible by 3 because the sum of its digits (7 + 9 + 1 + 5 + 4 = 26) is not divisible by 3.

Program

import java.util.Scanner;

public class DivisibleBy3 {
   public static void main(String args[]) {
      Scanner sc = new Scanner(System.in);
      System.out.println("Enter a number :");
      String num = sc.nextLine();
      int digitSum = 0;
     
      for(int i = 0; i<num.length(); i++) {
         digitSum = digitSum + num.charAt(i)-'0';
      }
      if(digitSum % 3 == 0) {
         System.out.println("Given number is divisible by 3");
      } else {
         System.out.println("Given number is not divisible by 3");
      }
   }
}

Output

Enter a number :
85203
Given number is divisible by 3