Top "Map" questions

increment map<string, int> using ++ operator

I have a map to count the occurrence of words in a file. I am reading words from the file, …

c++ map operators

Recommend a fast & scalable persistent Map - Java

I need a disk backed Map structure to use in a Java app. It must have the following criteria: Capable …

java map berkeley-db persistent berkeley-db-je

Iterate Java Map with index

How can I iterate a Map to write the content from certain index to another. Map<String, Integer> …

java collections map io writer

Other Ruby Map Shorthand Notation

I am aware of the shorthand for map that looks like: [1, 2, 3, 4].map(&:to_s) > ["1", "2", "3", "4"] I was told this …

ruby map shorthand

Idiomatic way to update value in a Map based on previous value

Let's say I store bank accounts information in an immutable Map: val m = Map("Mark" -> 100, "Jonathan" -> 350, "…

scala map immutability

How to change value(null to empty string) from query when using mybatis?

I am doing a project which uses Spring 3.1.1 and MyBatis3.0. I am trying to change iBatis to MyBatis. However, I …

map null mybatis ibatis typehandler

In Scala, is there a way to take convert two lists into a Map?

I have a two lists, a List[A] and a List[B]. What I want is a Map[A,B] …

list scala map scala-2.8 tuples

Method to extract all keys from LinkedHashMap into a List

I am working with many LinkedHashMap that are either LinkedHashMap<Long, Long>, LinkedHashMap<Long, Double> or …

java map hashmap key linkedhashmap

Fast algorithm to find the x closest points to a given point on a plane

I would like to find a fast algorithm in order to find the x closest points to a given point …

c# algorithm map point plane

What's the advantage of multimap over map of vectors?

I don't understand why multimap exists if we can create map of vectors or map of sets. For me only …

c++ stl map multimap