List:有序、索引、可以重复 List的特有方法:与索引相关的add\set\remove 迭代器的并发修改异常:在取元素的同时,继续往里面添加元素(下面包异常) 数组查询快,增删慢;链表查询慢,增删快 ArrayList:增删慢,查询快 LinkedList:增删快,查询慢 LinkedList的特有方法:addFirst addLast getFirst getL
HashSet is much faster than TreeSet (constant-time versus log-time for most operations like add, remove and contains) but offers no ordering guarantees like TreeSet. HashSet class offers constant time performance for the basic operations (add, remove, contains and size). it does not guarantee...