Introduction to Object-Oriented Programming

Study Notes

Known as structured programming, it organizes programs into functions or procedures.
Programs are designed as sequences of procedures, each doing a specific task.

OOP is a programming paradigm that uses objects as core components.
Objects represent real-world entities with attributes (data) and behaviors (functions/methods).

Organization: POP separates data and functions; OOP encapsulates data and functions within objects.
Reusability: POP allows function reuse with manual data management; OOP allows objects to be reused and extended via inheritance.
Maintainability: Maintaining POP can be complex as programs grow; OOP's encapsulation and modularity make it easier to manage changes.

Encapsulation: Bundling data and methods within a single unit (class).
Inheritance: Mechanism for one class to inherit properties and behaviors from another.
Polymorphism: Ability for different objects to respond to the same method call in unique ways.
Abstraction: Hides complex implementation details, exposing only essential features.
Modularity: Enables focused coding and understanding of specific system parts.
Reusability: Facilitates the repeated use of certain programs.
Constructor: Special method initialized when an object is created, setting up attributes.

A Class is a blueprint for creating objects, defining their structure and behavior.
Super Class: The base class or parent.
Sub Class: The derived class or child class.
Non-static Class: Requires instantiation to create objects.
Static Class: Can be used without instantiation.

An Object is an instance of a class, equipped with attributes and behaviors.
Attributes: Variables that represent characteristics of objects; they can be manipulated by methods.
State: Current values of an object's attributes, which can fluctuate based on method interactions.

A Method is an action performed by an object; functions defined in a class dictate object behavior.
Abstract Method: An empty method with no implementation provided.

An Interface defines a collection of methods, showcasing additional behaviors classes can implement beyond what they inherit.
Instance Method: Operates on individual object instances.
Static Method: Belongs to the class instead of an object; does not alter object attributes and can be invoked on the class itself.

Packages group related classes and interfaces in an organized structure.
They streamline access to classes while avoiding potential naming conflicts.
Java class libraries are found in the default package java, with basic features available in java.lang.