HashMap不能记住插入时的顺序,但LinkedHashMap可以做到这一点。
例程:
Map<Integer,String> empMap=new LinkedHashMap<Integer,String>(); empMap.put(4, "Doglas"); empMap.put(1005, "4232423432"); empMap.put(1, "Andy"); empMap.put(3, "Cindy"); empMap.put(5, "Edin"); empMap.put(2, "Bill"); for(int key:empMap.keySet()) { System.out.println(key+","+empMap.get(key)); }
输出:
4,Doglas 1005,4232423432 1,Andy 3,Cindy 5,Edin 2,Bill
而TreeMap则能做到按Key排序。
例程:
Map<Integer,String> empMap=new TreeMap<Integer,String>(); empMap.put(4, "Doglas"); empMap.put(1005, "4232423432"); empMap.put(1, "Andy"); empMap.put(3, "Cindy"); empMap.put(5, "Edin"); empMap.put(2, "Bill"); for(int key:empMap.keySet()) { System.out.println(key+","+empMap.get(key)); }
输出:
1,Andy 2,Bill 3,Cindy 4,Doglas 5,Edin 1005,4232423432
--END-- 2019-12-24 10:01