Java hashmap - Java tutorial - w3Schools - Chapter 43 English
Java HashMap
In the ArrayList chapter, you learned that Arrays store items as an ordered collection, and you have to access them with an index number (int type). A HashMap however, store items in "key/value" pairs, and you can access them by an index of another type (e.g. a String).
One object is used as a key (index) to another object (value). It can store different types: String keys and Integer values, or the same type, like: String keys and String values.
HashMap Size
Loop Through a HashMap
Access an Item
Remove an Item
Add Items
java hashmap example
java hashmap methods