数组集合之间的相互转化

数组转集合：

String[] a={"1","2","3","4"};

List list=Arrays.asList(a);

集合转数组

 

List<String> list=new ArrayList<String>();

 

list.add("aa");

 

 Object[] ary1 = list.toArray();

 

 System.out.println(ary1.length);