Quick sort (Implementation in Java)

Test.java

class QuickSort{
    public void quicksort(int[] arr, int start, int stop){
        if(start < stop){
            int left = start;
            int right = stop;
            int pivot = arr[start];

            while(arr[left] < pivot){
                left += 1;
            }

            while(arr[right] > pivot){
                right -= 1;
            }

            if(left <= right){
                int temp = arr[left];
                arr[left] = arr[right];
                arr[right] = temp;
                left += 1;
                right -= 1;
            }

            quicksort(arr, start, right);
            quicksort(arr, left, stop);
        }
    }
}

public class Test{
    public static void main(String[] args){
        QuickSort ob = new QuickSort();
        int[] arr = {5, 2, 3, 4, 1};
        int n = arr.length;
        ob.quicksort(arr, 0, n-1);
        System.out.println("After sorting");
        for(int i = 0; i < n; i++){
            System.out.print(arr[i] + " ");
        }
        System.out.println();
    }
}