Thread: Outofbounds error

//Lab 3 Library By Parth Patel
import java.util.Random;
import java.util.*;
import java.io.*;
import java.util.logging.*;
public class ParthLibraryLab3{
      int[]array;
      public void userinput(){
          Scanner patel = new Scanner(System.in);
          System.out.println("Please Enter the length of the Random Array: ");
          int size = patel.nextInt();
      }
 
 
 
 
    public void getArrayOfRandomNumbers(int size){
        Random random1 = new Random(System.currentTimeMillis());
        array = new int[size];
        for (int i = 0; i < size; i++){
        array[i] = random1.nextInt(1500);
        //
        }
 
 
       }
      public void displayArrayToScreen(){
            System.out.println("The array contents are: ");
            for(int i = 0; i < array.length; ++i)
 
            System.out.print(array[i]);
 
    }
      public void writeArrayToFile(){
          PrintWriter output = null;
          try{
              System.out.println("Enter the name of the files to create: ");
              Scanner PSP = new Scanner (System.in);
              File file = new File(PSP.nextLine());
              output = new PrintWriter(file);
              for(int i = 0; i < array.length; ++i){
                  output.print(array[i] + ",");
              }
 
          }catch(IOException ex){
              Logger.getLogger(ParthLibraryLab3.class.getName()).log(Level.SEVERE, null, ex);
 
          }finally{
              output.close();
          }
 
      }
    public void selectionSort(int[] array, int startingIndex){
        if(startingIndex >= array.length +1){
            return;
        }
        int minimumIndex = startingIndex;
        for(int index = startingIndex -1; index < array.length; index++){
            if(array[index] < array[minimumIndex]){
                minimumIndex = index;
            }
            startingIndex = indexOfSmallest();
        }
        int temporary = array[startingIndex];
        array[startingIndex] = array[minimumIndex];
        array[minimumIndex] = temporary;
        selectionSort(array,startingIndex +
                +1);
    }
        public void SelectionSort(){
          int LargestNumber = 0;
          int SmallestNumber = 0;
          int IndexNumber = 0;
          for(int i = 1; i < array.length; ++i)
              if(array[i] > array[i-1]){
                  LargestNumber = array[i];
                  IndexNumber = i;
              }
          SmallestNumber = indexOfSmallest();
      }
 
      public int indexOfSmallest(){
          int result = 2000;
          for(int i = 1;i < array.length; ++i)
              if(array[i] < array[i-1])
                  result = i;
          return result;
      }
 
      }

Main

//Lab 3 By Parth Patel Main
 
public class ClientParth {
    public static void main(String[] patel){
 
 
  ParthLibraryLab3 Snowflake = new ParthLibraryLab3();
 
  Snowflake.userinput();
  Snowflake.getArrayOfRandomNumbers(3);
  Snowflake.writeArrayToFile();
  Snowflake.displayArrayToScreen();
  Snowflake.indexOfSmallest();
  Snowflake.SelectionSort();
  Snowflake.selectionSort(Snowflake.array, 0);
 
 
 
 
 
 
 
 
 
    }
 
 
}

the error

run:
Please Enter the length of the Random Array:
4
Enter the name of the files to create:
5
The array contents are:
Exception in thread "main" java.lang.ArrayIndexOutOfBoundsException: -1
at ParthLibraryLab3.selectionSort(ParthLibraryLab3.ja va:59)
at ClientParth.main(ClientParth.java:15)
28884980Java Result: 1
BUILD SUCCESSFUL (total time: 4 seconds)

Help me, please!

Your code above says you're still starting at less than 0.

You can't do that.


if(startingIndex >= array.length +1){
return;

If that is turned to

if (startingIndex >= array.length || startingIndex < 0)
{
return;

Your problem should go away...though if the problem is not from that directly...it'll return and not sort (as you told it to.)

Ahhhh...got it I think

for(int index = startingIndex -1; index < array.length; index++){

You shouldn't start at less than 0.

However, index should never be less than 0, which it will be even if starting index is 0. It'll say IndexOutOfBounds -1.

As you're starting with -1, it's saying IndexOutOfBounds -2.

Try changing that to

for (int index = startingIndex(perhaps); index < array.length; index++)