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

Sep 6, 2009 · If I have the value "foo", and a HashMap<String> ftw for which ftw.containsValue("foo") returns true, how can I get the corresponding key? Do I have to loop through the hashmap? What is …

805 Suppose we have a HashMap<String, Integer> in Java. How do I update (increment) the integer-value of the string-key for each existence of the string I find? One could remove and reenter the pair, …

Is checking for key existence in HashMap always necessary? I have a HashMap with say a 1000 entries and I am looking at improving the efficiency. If the HashMap is being accessed very frequently, ...

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 includes for …

May 6, 2011 · What is the easiest way to get key associated with the max value in a map? I believe that Collections.max(someMap) will return the max Key, when you want the key that corresponds to the …

Jun 15, 2012 · Java HashMap key value storage and retrieval Asked 13 years, 6 months ago Modified 4 years, 1 month ago Viewed 105k times

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.) Method #1: …

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 tables to...

Apr 23, 2009 · How are we able to sort a HashMap&lt;key, ArrayList&gt;? I want to sort on the basis of a value in the ArrayList.