collections用法以及list 简单实例
Collection<Integer> collection = new ArrayList<Integer>(Arrays.asList(1,2,3,4,5)); Integer[] moreIntegers = {6,7,8,9}; collection.addAll(Arrays.asList(moreIntegers)); Collections.addAll(collection,11,12,13,14,15); Collections.addAll(collection,moreIntegers); List<Integer> list3 = Arrays.asList(16,17,18); list3.set(1, 99); List<Integer> list4 = new ArrayList<Integer>(); list4.add(33); list4.set(0, 99); System.out.println(list4);
[1, 2, 3, 4, 5, 6, 7, 8, 9, 11, 12, 13, 14, 15, 6, 7, 8, 9] [16, 99, 18] [99]