[javase] Collection

[Alice52]

• https://juejin.im/post/6877313264988979213

Collection

Array

Set

List

1. LinkedList and ArrayList:

   • using ArrayList to query
   • using ArrayList to insert in middle
   • using ArrayList to insert tail element is perfomance better
   • using LinkedList to insert into top

   

[Alice52]

List 去重: deduplicate

1. LinkedHashSet

   LinkedHashSet<Integer> hashSet = new LinkedHashSet<>(numbersList);
   ArrayList<Integer> listWithoutDuplicates = new ArrayList<>(hashSet);

2. stream: distinct
3. 遍历自己写
4. HashSet: 不稳定