Top "Hashmap" questions

A data structure that uses a hash function to map identifying values, known as keys, to their associated values

Why use symbols as hash keys in Ruby?

A lot of times people use symbols as keys in a Ruby hash. What's the advantage over using a string? …

ruby string hashmap symbols
Find the Biggest number in HashSet/HashMap java

I would like to find the biggest number in HashSet and HashMap. Say I have the number [22,6763,32,42,33] in my HashSet …

java hashmap hashset
Which is faster, Hash lookup or Binary search?

When given a static set of objects (static in the sense that once loaded it seldom if ever changes) into …

algorithm hash hashmap lookup binary-search
java.lang.NullPointerException: println needs a message

I get the errror: java.lang.NullPointerException: println needs a message when I call this method: lst_info = new HashMap&…

android nullpointerexception hashmap println
Does Java have a HashMap with reverse lookup?

I have data that is organized in kind of a "key-key" format, rather than "key-value". It's like a HashMap, but …

java map hashmap bidirectional reverse-lookup
Using tuple in unordered_map

I want to use tuple consisting of int,char,char in my unordered_map. I am doing like this: #include &…

c++ hashmap unordered-map stdtuple
What is a hash map in programming and where can it be used

I have often heard people talking about hashing and hash maps and hash tables. I wanted to know what they …

hashtable hashmap hash
Internal implementation of java.util.HashMap and HashSet

I have been trying to understand the internal implementation of java.util.HashMap and java.util.HashSet. Following are the …

java hashmap hashcode hashset language-implementation
Displaying Hashmap keys and values in a primefaces DataTable

I'm trying to display a Hashmap in a DataTable, here's what i'm trying to do : I'll have a select menu …

java jsf primefaces hashmap
Using the keySet() method in HashMap

I have a method that goes through the possible states in a board and stores them in a HashMap void …

java hashmap hashset linkedhashset