Collections in Java

HashMap: Creation and Insertion

Explore how to create HashMaps in Java using various constructors including default, with initial capacity, and with load factor. Understand how to insert elements using put, putIfAbsent, and putAll methods while learning their behaviors for updating or preserving values.

We'll cover the following...

Creating a HashMap

Using the no-arg constructor
Using the constructor that takes initial capacity
Using the constructor that takes initial capacity and load factor
Using the constructor that takes another Map as a parameter

Inserting into a HashMap

Using the put() method
Using the putIfAbsent() method
Using the putAll() method