Differences between HashMap and HashTable in Java HashMap and Hashtable store key/value pairs in a hash table. When using a Hashtable or HashMap, we specify an object that is used as a key, and the value that you want linked to that key. HashMap vs Hashtable vs LinkedHashMap vs TreeMap - Differences HashMap vs IdentityHashMap - Similarity and Differences with program TreeMap vs ConcurrentSkipListMap - Similarity and Differences with program Map hierarchy tutorial in java - Detailed - java.util. HashMap, java.util. Hashtable, java.util.concurrent. ConcurrentHashMap, java.util Java HashMap getOrDefault() Example Below is a java code demonstrates the use of getOrDefault() method of HashMap class. The example presented might be simple however it shows the behavior of the getOrDefault() method. In this post we will see the main differences between these two collections. ArrayList vs HashMap in Java. 1) Implementation: ArrayList implements List Interface while HashMap is an implementation of Map interface. List and Map are two entirely different collection interfaces. Difference Between HashMap VS LinkedHashMap VS TreeMap In Java Last Updated on: March 14, 2019 By SoftwareTesting0 In this article, we will compare important implementation classes of Map i.e.; HashMap v/s LinkedHashMap v/s TreeMap At entry level Java programmer, you can expect this interview question on Hashtable vs HashMap.Though the question becomes really easy when you know other concepts like how hashmap works, yet after getting a many queries from my blog readers who are preparing for or working at junior level, I have decided to summarize my knowledge on differences between HashMap and a Hashtable. Java Tutorials,Scala Tutorials,Interview questions,Struts,Spring,HTML5,Design patterns,Java Puzzle,Java Quiz,jQuery Tutorials,jQuery This article explains differences between HashMap, ConcurrentHashMap, HashTable and Collections.synchronizedMap If multiple threads access a hash map Map use