sum of numbers in java code example

Example 1: sum of digits in java

import java.io.*;
public class sd
{
  public static void main(String [] args)throws IOException
  {
     InputStreamReader hi = new InputStreamReader(System.in);
        BufferedReader in = new BufferedReader(hi);
        System.out.println("Enter the number");
        int num=Integer.parseInt(in.readLine());
    int sum=0;
    while(num>=0)
    {
      int rem=n;
      sum+=rem;
      int quo=n/10;
      n=quo;
    }
    System.out.println(sum);
  }
}

Example 2: java accept 2 integers from the user, and using a method add these numbers and print the result

static void M1(int num1, int num2) {
        int sum = num1 + num2;
        System.out.println("sum of " + num1 + " and " + num2+ " = " + sum);    
    }
 
    public static void main(String[] args) {
        // using Methods
        Scanner input = new Scanner(System.in);
        int num1,num2;
        System.out.println("Enter a number: ");
        num1 =input.nextInt();
        System.out.println("Enter 2nd number: ");
        num2 =input.nextInt();
        input.close();
        M1(num1, num2);
    }
}

Example 3: sum of numbers in java

public class SumNatural {

    public static void main(String[] args) {

        int num = 100, sum = 0;

        for(int i = 1; i <= num; ++i)
        {
            // sum = sum + i;
            sum += i;
        }

        System.out.println("Sum = " + sum);
    }
}