LinkedHashMap 概述

java.util.LinkedHashMap<k,v>集合 extends HashMap<k,v>集合

LinkedHashMap的特点:

1. LinkedHashMap集合底层是哈希表+链表(保证迭代的顺序)：查询速度快

2. LinkedHashMap集合是一个有序的集合,存储元素和取出元素的顺序是一致的

Demo：

HashMap<String,String> map = new HashMap<>();
       map.put("a","a");
       map.put("c","c");
       map.put("b","b");
       map.put("a","d");
       System.out.println(map);// key不允许重复,无序 {a=d, b=b, c=c}
       LinkedHashMap<String,String> linked = new LinkedHashMap<>();
       linked.put("a","a");
       linked.put("c","c");
       linked.put("b","b");
       linked.put("a","d");
       System.out.println(linked);// key不允许重复,有序 {a=d, c=c, b=b}

转自: https://www.cnblogs.com/niujifei/p/11443934.html

Java 之 LinkedHashMap 集合

LinkedHashMap 概述