Question

/*
 * Application the reads an integer and prints sum of all even integers between two and input    value
 */

import java.util.Scanner;

public class evenNumbers{

  public static void main(String [] args){
    int number;
    Scanner scan = new Scanner(System.in);
    System.out.println("Enter an Integer greater than 1:");
    number = scan.nextInt();
    printNumber(number);
  }// end main


  /*declares an int variable called number and displays it on the screen*/
  public static void printNumber(int number){
    if (number < 2){
      System.out.println("Input value must not be less than 2");
    }
    int sum = 2;
     if(number % 2==0){
       sum+= number;
     }
     System.out.println("Sum of even numbers between 2 and " + number + " inclusive is: " + sum);

  }//end printnumber
}

I need to calculate the sum of 2 to the input number inclusive however, it only takes the last number and add two to it. COuld someone help me fix this.

Answer 1

You need a loop. Your comment hints at the right direction, but you should look at the Java tutorials to see how to correctly write a ‘for’ loop. There are three parts: the initial declaration, the terminating condition and the loop step. Remember that the ++ operator only adds one to the variable. You can add other values using +=. If you use += to add a different value (like 2) to the loop variable, you can skip the ‘if’ test for even numbers. You can test for boundaries inclusively using the <= and >= comparison operators (for primitives). So you want something like this (in pseudocode, not Java):

 input the test value 
 Optional: reject invalid test value and **exit with message if it is not valid!** 
 initialize the sum variable to zero
 for ( intialize loop variable to 2; test that loop var <= test value; add 2 to loop var ) 
 { 
    add 'number' to the sum variable 
 } 
 display the sum