### Question:
QuickSort { public void sort(int[] values) { if (values ==null || values.length==0){ return; } this.numbers = values; number = values.length; quicksort(0, number - 1); }  void sort(int[] values);  }### Answer:
@Test public void demoTest(){ int[] values = new int[]{3,7,8,5,2,1,9,5,4}; QuickSort sorter = new QuickSort(); for (int value : values){ System.out.print(value + " "); } System.out.println(); System.out.println("----------------------------------"); sorter.sort(values); for (int value : values){ System.out.print(value + " "); } }