📜  设置了什么 - 无论代码示例

📅  最后修改于: 2022-03-11 14:57:50.642000             🧑  作者: Mango

代码示例3
SET: Can only store unique values, 
     And does not maintain order
- HashSet can have null, order is not guaranteed
- LinkedHashSet can have null and keeps the order 
- TreeSet sorts the order and don't accept null