title: How do i fix this runtime error? Exception in thread "main" java.lang.ArrayIndexOutOfBoundsException: -1
body: <pre><code>import java.util.Scanner;  //importing scanner to get user input
  
  public class ArrayHelper
  {
      public static void main(String[] args)
      {
          Scanner input = new Scanner(System.in);
          int[] hello = new int[10];
          for(int i = 0; i &lt; 10; i++) //to get right number of integers
          {
              System.out.print("Please enter an integer: ");
              hello[i] = input.nextInt();
          }
  //printing everything out 
          display(hello);
          System.out.println();
          System.out.print("Evens: ");
          display(onlyEvens(hello));
          System.out.println();
          System.out.print("Positives: ");
          display(onlyPositives(hello));
          System.out.println();
          System.out.print("Odds: ");
          display(disjoint(hello ,onlyEvens(hello)));
          System.out.println();
          System.out.print("Negatives: ");
          display(disjoint(hello ,onlyPositives(hello)));
          System.out.println();
      }
  
      public static void display(int[] nums)
      {
          for(int i = 0; i &lt; nums.length -1; i++)
              System.out.print(nums[i] + ", ");
  
          System.out.print(nums[nums.length - 1]); //!!!!!!this is where the error occurs
      }
      public static int[] onlyEvens(int[] nums) //only even numbers in array (anything divisible by 2 including 0)
      {
          int x = 0;  //for set length
          for(int i = 0; i &lt; nums.length; i++)
              if (nums[i]%2 == 0) //checks if even
                  x++;
  
          int[] y = new int[x];
          int z = 0;
  
          for(int i = 0; i &lt; nums.length; i++)
              if (nums[i]%2 == 0) //checks if even
              {
                  y[z] = nums[i];
                  z++;
              }
          return y;
      }
      public static int[] onlyPositives(int[] nums) //looking for only positive integers in array
      {
          int x = 0;  //sets set length
          for(int i = 0; i &lt; nums.length; i++)
              if (nums[i] &gt; -1)   //checks if positive
                  x++;
  
          int[] y = new int[x];
          int z = 0;
  
          for(int i = 0; i &lt; nums.length; i++)
              if (nums[i] &gt; -1)   //checks if positive
              {
                  y[z] = nums[i];
                  z++;
              }
  
          return y;
      }
  
      public static int[] disjoint(int[] nums, int[] nums2)
      {
          int x = 0;
  
          for(int i = 0; i &lt; nums.length; i++)
          {
              int j = nums[i];
              if(!contains(nums2 , j))    //checks if letter be there
                  x++;
          }
  
          for(int i = 0; i &lt; nums2.length; i++)
          {
              int j = nums2[i];   //checks if letter be there
              if(!contains(nums , j))
                  x++;
          }
  
          int[] y = new int[x];
          int z = 0;
  
          for(int i = 0; i &lt; nums.length; i++)
          {
              int j = nums[i];    //checks if letter be there
              if(!contains(nums2 , j))
              {
                  y[z] = nums[i];
                  z++;
              }
          }
  
          for(int i = 0; i &lt; nums2.length; i++)
          {
              int j = nums2[i];   //checks if letter be there
              if(!contains(nums , j))
              {
                  y[z] = nums2[i];
                  z++;
              }
          }
          return y;
      }
  }
  </code></pre>
  
  <p>this is a program that takes in user input to get 10 integers to create an array. I have all of the program done, and there are no compile time errors, but when I run the code, there's an index out of bounds (-1) problem in the display method and ive done everything to try and fix it. thank you!</p>