Apr 7, 2010 · Hashmap is used for storing data in key value pairs. We can use a hashmap for storing objects in a application and use it further in the same application for storing, updating, …

What are the differences between a HashMap and a Hashtable in Java? Which is more efficient for non-threaded applications?

64 Map is an interface that HashMap implements. The difference is that in the second implementation your reference to the HashMap will only allow the use of functions defined in …

A hash_map is an older, unstandardized version of what for standardization purposes is called an unordered_map (originally in TR1, and included in the standard since C++11). As the name …

Jul 1, 2009 · Since all maps in Java implement the Map interface, the following techniques will work for any map implementation (HashMap, TreeMap, LinkedHashMap, Hashtable, etc.) …

Apart from the fact that HashSet does not allow duplicate values, what is the difference between HashMap and HashSet in their implementation? It's a little bit vague because both use hash …

I'm using a HashMap. When I iterate over the map, the data is returned in (often the same) random order. But the data was inserted in a specific order, and I need to preserve the …

On an average, the time complexity of a HashMap insertion, deletion, and the search takes O (1) constant time in java, which depends on the loadfactor (number of entries present in the hash …

Use of generic args on the outer HashMap would seem to indicate Java 5 or later. [ [ But I did wonder about what Java this was since the inner HashMap didn't have generic args and there …

I've seen some interesting claims on SO re Java hashmaps and their O(1) lookup time. Can someone explain why this is so? Unless these hashmaps are vastly different from any of the …