Object-Oriented Programming

Abstract classes are designed to be incomplete and cannot be directly instantiated using the 'new' keyword. They serve as templates for subclasses and must be extended before their functionality can be used. Only concrete subclasses of abstract classes can be instantiated.

In Java, applets can extend either the Applet class (from AWT) or the JApplet class (from Swing). JApplet is the Swing alternative to AWT's Applet class, providing the same functionality with Swing's improved UI components and capabilities.

An abstract class can be used to partially implement an interface. The abstract class provides implementations for some methods while leaving others abstract, forcing concrete subclasses to implement the remaining interface methods.

The 'extends' keyword in Java is used for inheritance and is always followed by the base class (parent class) name. The child class inherits properties and behaviors from the base class, establishing an 'is-a' relationship between them.

The super() call is used in Java to invoke the constructor of the base (parent) class from a child class constructor. This allows the child class to initialize inherited properties and behaviors defined in the parent class, ensuring proper initialization throughout the inheritance chain.

This storage class concerns itself with the permanence of variables.

In this storage class, the variables are created when the program is run and destroyed when the program is exited.

A class serves as a blueprint or template that defines the structure and behavior common to all objects of that type. It specifies what data (variables/attributes) and operations (methods/functions) every object created from that class will have. Objects are instances created from this blueprint.

Method overloading allows a class to have multiple methods with the same name but different parameter lists (different number or types of parameters). The compiler selects which version to call based on the arguments passed. This is different from overriding (replacing a parent class method) and enables method behavior to vary based on input types.

Constructors have the same name as their class (statement II is true) and can be overloaded to provide multiple initialization options (statement III is true). Statement I is false because while constructors have no return type, they are not void methods. Statement IV is false because constructors are called automatically during object creation, not like regular methods.