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Thread: How to add all even numbers between 2 and a user input number which is included in the Addition

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    Default How to add all even numbers between 2 and a user input number which is included in the Addition

    import java.util.*;
     
    public class SumOfAllEvens {
     
    	public static void main (String[] args)
    	{
     
    		Scanner s = new Scanner (System.in);
     
    		//for (int i=1; i<4; i++){
    		int usernumber; 
    		int sum=0;
     
    		System.out.print ("Please enter an integer: "); // Prompt
    		usernumber = s.nextInt();
     
    		for (int j=2; j<=usernumber; j=j+2){
     
     
     
    		if (usernumber<2)
    			System.out.println ("Error");
    		else
    			System.out.println ("The sum of all evens from 2 to " + usernumber + " (inclusive) is " + (j+usernumber) + " .");
     
    					//sum=sum+j;
     
    		//}
    		}
    	}
    }

    I'm supposed to use a for loop that runs until it reaches the number input by the user, but I'm not sure how to tell the program to add the user's number along with all of the even numbers in between the user input and 2.


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    Default Re: How to add all even numbers between 2 and a user input number which is included in the Addition

    On each iteration of the loop, what number do you want to add to the sum?
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    Default Re: How to add all even numbers between 2 and a user input number which is included in the Addition

    Quote Originally Posted by KevinWorkman View Post
    On each iteration of the loop, what number do you want to add to the sum?
    The sum is supposed to be all of the even numbers between 2 and the number which the user inputs. The user input number is also included in the sum. So basically if the user inputs say, 10, the sum would be 2+4+6+8+10.

    If the user inputs an odd number such as 7, it'd be 2+4+6+7.

    The part i'm most confused about is telling the computer what the number is that the user input and not adding it twice if it's an even number.

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    Default Re: How to add all even numbers between 2 and a user input number which is included in the Addition

    You might want to look into the modulus operator for determining whether a number is even or odd.
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    Default Re: How to add all even numbers between 2 and a user input number which is included in the Addition

    You can take a loop from 2 to the inputted number and put increment of 2 and then add the value of the loop suppose x add it to s variable for sum and initialize it as 0 s=s+x;

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