Learn about ConcurrentHashMap vs. SynchronizedMap in Java concurrency. Code example & performance analysis. Boost your Java programming skills with Crunchify! HashMap is a very powerful data …
Hashmap • Tag Archive
Interview questions on Java HashMap, Data structure, etc are the most common and fundamental concepts. On Crunchify, we do have more than hundreds of tutorials for you to use free of charge.
How to Sort a HashMap by Key and Value in Java 8 – Complete Tutorial
In Java 8 – How to sort a Map? On Crunchify we have written almost ~400 java tutorials and this one is an addition to Java8 category. I love Java collection and have multiple tutorials on How to …
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Java Hashmap – containsKey(Object key) and containsValue(Object value) – Check if Key/Value Exists in Map
There are few concepts and technologies which comes by default with each and every programing language and Collection is one of them. Java Collection is a very big field. It comes …
How to use net.jodah.ExpiringMap Maven Java Utility to Remove Expired Objects from HashMap Automatically?
Java without Java Collection is really hard to imagine. I spend almost couple of hours a day working on Java Projects for my clients. HashMap, Map, Static Objects, Java Interface are the …
In Java how to Initialize HashMap? 7 different ways
In Java How to initialize HashMap? How to directly initialize a HashMap (in a literal way). There are 7 different ways you can initialize HashMap in Java. Method-1: Simple Mutable map: It's …
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In Java What is a Difference Between IdentityHashMap and HashMap + Performance Comparison
Sometime back I have a special case in which I have to compare Map's Key based on equality operator (==). The equality operator (==) compares the references (addresses in memory) of the two …
How to Remove expired elements from HashMap and Add more elements at the Same Time – Java Timer, TimerTask and futures() – Complete Example
Hashmap, ArrayList, Static Map, Vectors, etc are the most used Java collection framework elements. There are infinite number of scenarios you could use this as per your need. This example is very …
How to convert HashMap to ArrayList in Java?
Here is a simple example on how to convert HashMap to ArrayList in Java. Java Example: package com.crunchify; /** * @author Crunchify.com */ import java.util.ArrayList; import …
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Java: How to find Unique Values in ArrayList (using TreeSet, HashSet)
This tutorial gives you simple way to find unique values in ArrayList using TreeSet and HashSet. HashSet is much faster than TreeSet (constant-time versus log-time for most operations like add, remove …
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Java: How to Get Random Key-Value Element From HashMap
Is there a way to get the value of a HashMap randomly in Java? Of Course, below is a simple Java Code which represents the same. Also, at the end of program there is a bonus code to Shuffle …
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Implement Simple Threadsafe Cache using HashMap without using Synchronized Collection
A cache is an area of local memory that holds a copy of frequently accessed data that is otherwise expensive to get or compute. Examples of such data include a result of a query to a database, a disk …