i am trying to perform this on another set if numbers (the numbers i commented out in the main class) but i am still getting an out of bound exeption

public class DataStructuresLab_4 {

/**

* @param args the command line arguments

*/

public static void main(String[] args) {

QuickSelect quickSelect = new QuickSelect();

int[] intArray = {9,12,5,17,20,30,8};

int k = quickSelect.quickSelect(intArray, 0, 6, 4);

//********************************************8

// int[] intArray = {12,5,19,2,15,24,18,16};

// int k = quickSelect.quickSelect(intArray, 0, 7, 4);

System.out.println("The Kth smallest number is "+k);

}

public class QuickSelect {

public int quickSelect(int[] intArray,int l, int r, int k){

int s = partition(intArray,l,r);

if (s == l+k-1){

//1+k-1

return intArray[s];

}else if (s > l + k -1){

return quickSelect(intArray, l,s-1,k);

}else{

return quickSelect(intArray, s+1,r,k+l-1-s);

}

}

public int partition(int[] intArray,int l, int r){

int p = intArray[r];

int s = l;

for (int i =l ; i < r; i++){

//0 + 1

if(intArray[i] < p){

int t = intArray[s];

// intArray[i] = intArray[s];

intArray[s] = intArray[i];

intArray[i] = t;

s = s+1;

}else{

int t = intArray[r];

intArray[r] = intArray[s];

intArray[s] = t;

return s;

}

//return s;

}

return 0;

}

}