HashMap class in Java

This text aims to introduce HashMap and how to use it in Java programs. In the series of Map involved articles,

HaspMap is implemented from Map interface and inherited from AbstractMap class (as shown in Fig. 1).

HashMap works on the principle of Hashing.

HashMap vs. TreeMap vs. Hashtable vs. LinkedHashMap

https://www3.ntu.edu.sg/home/ehchua/programming/java/J5c_Collection.html

https://dzone.com/articles/an-introduction-to-the-java-collections-framework

https://www.karambelkar.info/2012/06/java-1.7-collections—uml-class-diagrams/

https://docs.oracle.com/javase/8/docs/api/java/util/HashMap.html