????8.  ??????????б?????????
????String[] stringArray = { "a"?? "b"?? "c"?? "d"?? "e" };
????ArrayList<String> arrayList = new ArrayList<String>(Arrays.asList(stringArray));
????String[] stringArr = new String[arrayList.size()];
????arrayList.toArray(stringArr);
????for (String s : stringArr)
????System.out.println(s);
????9.  ?????????????????set??
????Set<String> set = new HashSet<String>(Arrays.asList(stringArray));
????System.out.println(set);
????//[d?? e?? b?? c?? a]
????10.  ???????????
????int[] intArray = { 1?? 2?? 3?? 4?? 5 };
????ArrayUtils.reverse(intArray);
????System.out.println(Arrays.toString(intArray));
????//[5?? 4?? 3?? 2?? 1]
????11.  ????????е????
????int[] intArray = { 1?? 2?? 3?? 4?? 5 };
????int[] removed = ArrayUtils.removeElement(intArray?? 3);//create a new array
????System.out.println(Arrays.toString(removed));
????12.  ?????????????????
????byte[] bytes = ByteBuffer.allocate(4).putInt(8).array();
????for (byte t : bytes) {
????System.out.format("0x%x "?? t);
????}