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

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, …

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 …

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 …

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 …

Jan 13, 2016 · Tengo una estructura en HashMap y necesito iterarla a través de un for. Como puedo hacer esta iteración? Mi código: import java.util.HashMap; import java.util.Map; public …

So key for this HashMap is couresID, and value is a ArrayList of all grades (exam attempts) this person has made. The problem is I know how to work with array lists and hashmaps normally, …

Sep 17, 2015 · Note that there is a difference between the "Map" abstract data type and the Map Java interface. As mentioned in other answers, the legacy Dictionary class does not …

Aug 6, 2014 · HashMap in Java is a widely used data structure, which allows key-value pairs to be stored and retrieved in constant time. In this article, we will look into how the get () and put () …