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?

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.) …

Jan 5, 2017 · 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 …

As you have HashMap<String, HashMap>, you would need two loops - one for the outer and one for the inner HashMap. Btw - you should definitively type the second HashMap - don't know …

Mar 26, 2013 · I am still new to object instantiation, and wonder what to do to initialize a HashMap of HashMaps. When inserting new observations into the classifier, I can create a new …

May 5, 2012 · 1 To get keys in HashMap, We have keySet () method which is present in java.util.Hashmap package. ex :

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 …

Map<String, String> myMap = new HashMap<String, String>() {{ put("a", "b"); put("c", "d"); }}; However, the anonymous subclass might introduce unwanted behavior in some cases. This …

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 …