TreeSet and LinkedHashSet. When and which to use is an important question. In brief, if you need a fast set, you should use HashSet; if you need a sorted set, then TreeSet should be used; if you need a set that can
e.g.SortedSet<String> s = new TreeSet<String>(hashSet); Mapis an important data structure. 1. Map Overview There are 4 commonly used implementations of Map in Java SE - HashMap, TreeMap, Hashtable and LinkedHashMap. If we use one sentence to describe each implementation, it would be...
Java集合之Set —— HashSet、TreeSet及LinkedHashSet 神图镇楼 1.HashSet 内部由哈希表实现,HashSet中的数据是无序的(说是无序,其实只是对coder而言,底层还是有一套算法实现排序的),可以放入null,存储对象不重复。 输出结果:[null, 0, 1, 4, 5] 2.TreeSet 内部由二差树(红黑树的数据结构)实现,Tree...
Use tips: A LinkedHashSet is an ordered version of HashSet that maintains a doubly-linked List across all elements. Use this class instead of HashSet when you care about the iteration order. When you iterate through a HashSet the order is unpredictable, while a LinkedHashSet lets you itera...
Summary of LinkedHashSet:http://www.programcreek.com/2013/03/hashset-vs-treeset-vs-linkedhashset/ A Set contains no duplicate elements. That is one of the major reasons to use a set. There are 3 commonly used implementations of Set: HashSet, TreeSet and LinkedHashSet. When and which ...