Java Object-Oriented Programming

Object-Oriented Programming (OOP) shifts the focus from procedural logic to modeling software around objects that contain both data and the methods to manipulate that data.

In Java, the 'class' keyword is used to define the blueprint for objects.

In OOP, a procedure or function defined within a class that describes an action an object can perform is called a method.

Member functions can have different access modifiers, such as public, private, or protected, to control their visibility and accessibility.

Constructors are special methods invoked during the creation of an object to initialize its state.

Encapsulation is the OOP principle of keeping object details private and providing access only through member functions. This hides internal implementation details and protects data integrity by controlling how external code can interact with an object's state.

Abstract classes are incomplete by design and cannot be instantiated directly; they must be extended by a concrete subclass.

Polymorphism allows objects to be treated as instances of their parent class, with the specific method implementation determined at runtime through dynamic binding.

Method overloading occurs when multiple methods in the same class share the same name but have different parameter lists.

Polymorphism (from Greek, meaning 'many forms') is the ability of an object to take on many forms, often through inheritance or interfaces.

A class serves as the template or blueprint from which individual objects are created.

The 'super' keyword is used in object-oriented languages to refer to the immediate parent class, allowing access to its methods and variables.

Method overriding occurs when a subclass provides a specific implementation for a method that is already defined in its superclass, using the same signature.

The main method is a static entry point for the JVM and cannot be overridden in the traditional sense of polymorphism.

Constructors are special methods that do not have a return type, not even 'void'.

Multithreading is a feature of concurrent programming, not a core principle of Object-Oriented Programming (which includes encapsulation, inheritance, and polymorphism).

Every object in an OOP system is characterized by its state (data/fields) and its behavior (methods/actions).

In object-oriented programming, sending a message to an object is the mechanism by which an operation is invoked. This results in the execution of a method defined within that object's class.

Inheritance allows a subclass to acquire the properties (data) and behaviors (methods) of a parent class. This promotes code reuse and hierarchical organization.

Inheritance is a fundamental OOP concept used to extend existing classes. It allows developers to create new classes that reuse and build upon the functionality of existing ones without modifying the original source code.

In Java, if a class does not explicitly define any constructors, the compiler automatically provides a default, no-argument constructor. The other options are incorrect because classes and objects are distinct entities, and classes are not required to have member functions.