What is a class?

Class definition

A class is a set of parameters and methods that define the abstraction of an object. A class has the following elements:

• Fields: these are the parameters
• Constructor: method that creates a new class object. A constructor can accept input parameters to initialize
• Methods: functions that can use the fields values to compute required outputs or update its own fields

Difference between class and object

• An object is an instance of a class
• Each object is independent of any other object of the same class

Ways to create an object

There are several ways to create an object:

• Using the new operator: the most common way to create an object in Java.
• Using the clone() method: if you want to create a copy of an existing object.
  • To use it, implement the Cloneable interface in your class and override the clone() method
• Using factory methods: it is a static method that returns an instance of a class
  • Factory methods are often used to create objects when you need more flexibility or control over the object creation process
• Using reflection: feature of the Java language that allows you to inspect and manipulate the structure of a class at runtime.
  • To use it, invoke the newInstance() method on the Constructor object for a particular class
• Using deserialization: create an object from its serialized form, which is a stream of bytes that represents the object’s state
  • This method allows to persist the state of the execution and retrieve it when requested
  • To use it, the class must implement the Serializable interface and use ObjectInputStream and ObjectOutputStream classes to serialize and deserialize the object