What are Java Collections and how do I use them?

What are Java Collections and how do I use them?

Java Collections are a framework that provides classes and interfaces for storing and manipulating groups of objects. They include lists, sets, and maps.

Can you explain the difference between a List and a Set?

Sure! A List allows duplicate elements and maintains the order of insertion, while a Set does not allow duplicates and does not guarantee any specific order.

How do I create a HashMap in Java?

You can create a HashMap by using the syntax: HashMap<KeyType, ValueType> map = new HashMap<>(); Then, you can add key-value pairs using map.put(key, value);.

What are some common methods used with ArrayList?

Common methods include add(), remove(), get(), size(), and contains(). These methods help manage the elements in the ArrayList.