Quicksort random array

[xThrash]

Hello everyone,
I have some code to sort a random array of integers, although im getting an error whenever I try to run the method. It prints the input and then I get an error. The code is below and the error is below that.
If anyone could help me that would be great!

import java.util.Random;
public class quickSort{
    public static void main(String a[]){
        long start, end, total;
        start = System.nanoTime();
        Random r = new Random();
        int i;
        int [] array = new int [100];
        for (int k = 0; k < array.length; k++){
            array[k] = (r.nextInt(1000)+1);
        }
        System.out.print("Quick Sort Algorithm");
        System.out.print("\n\nInput: ");
        for(i = 0; i < array.length; i++)
            System.out.print( array[i]+"  ");
        quicksort(array,0, array.length);  
        System.out.print("\n\nOutput: ");
        for(i = 0; i < array.length; i++)
            System.out.print(array[i]+"  ");
        end = System.nanoTime();
        total = end - start;
        System.out.print("\n\nTime to execute = "+total+" nanoseconds\n\n");
    }

    public static void quicksort (int array[], int lo, int hi)
    {
        int i=lo, j=hi, h;
        int x=array[(lo+hi)/2];
        do
        {    
            while (array[i]<x) i++; 
            while (array[j]>x) j--;
            if (i<=j)
            {
                h=array[i]; array[i]=array[j]; array[j]=h;
                i++; j--;
            }
        } while (i<=j);
        if (lo<j) quicksort(array, lo, j);
        if (i<hi) quicksort(array, i, hi);
    }
}

java.lang.ArrayIndexOutOfBoundsException: 100
at quickSort.quicksort(quickSort.java:32)
at quickSort.main(quickSort.java:16)

Thanks in advance

[stultuske]

ArrayIndexOutOfBoundsException means that you try to assign - read an element of an array that doesn't exist. for instance:

int[] intRow = new int[5];
intRow[5] = 5;

this will throw an ArrayIndexOutOfBoundsException, since you're trying to assign an element (intRow[5]) that doesn't exist. the row just has 5 elements, which means it only goes up to: intRow[4]

[xThrash]

ArrayIndexOutOfBoundsException means that you try to assign - read an element of an array that doesn't exist. for instance:

int[] intRow = new int[5];
intRow[5] = 5;

this will throw an ArrayIndexOutOfBoundsException, since you're trying to assign an element (intRow[5]) that doesn't exist. the row just has 5 elements, which means it only goes up to: intRow[4]

Thanks for the reply.
So if that is the case with my code, how can I change it? I personally cant see whats wrong with it :/

Thanks again

[stultuske]

basicly, the sollution for your problem can be found in my previous post:
you're telling your quicksort method:

j = array.length => this means: j = 100

and the, you go and ask for the value of array[100]
==> while (array[j]>x) j--;

so, you're asking for the 101'th element, and that's where your exception occurs.