集合转变为数组
- 调用toArray() 静态方法
Object[] objects = collection3.toArray();
for (int i = 0; i < objects.length; i++) {
System.out.println(objects[i]);
}
数组变为集合
- 调用Arrays 类的静态方法 asList()
List strings = Arrays.asList(new String[]{
"AA", "BB", "CC"});