OOP Flashcards
Class:
Blueprint for creating objects. It defines a data structure that includes data members (fields) and methods.
Object:
An instance of a class. It represents a real-world entity and has state and behavior.
Inheritance:
Mechanism where a new class inherits properties and behaviors from an existing class. It promotes code reuse.
Polymorphism
Ability of a class to take on multiple forms. It allows objects of different classes to be treated as objects of a common base class.
Encapsulation
Bundling of data (attributes) and methods that operate on the data within a single unit (class). It restricts direct access to some of an object’s components.
Abstraction
Concept of hiding complex implementation details and showing only the necessary features of an object.
Constructor
Special method used for initializing objects. It is called when an object is created.
Method Overloading
Defining multiple methods in the same class with the same name but different parameters.
Interface
A collection of abstract methods. It defines a contract for classes that implement it.
Package:
A way to organize related classes into a single directory. It helps in avoiding naming conflicts.
Access Modifiers:
Keywords (public, private, protected) that control the visibility of class members (attributes and methods).
Final Keyword:
A keyword used to make a class, method, or variable unmodifiable or prevent inheritance.
Static Keyword:
A keyword used to define class members that belong to the class rather than instances of the class.
This Keyword:
A keyword used to refer to the current instance of the class. It is used to distinguish between instance variables and method parameters.
Super Keyword:
A keyword used to refer to the superclass. It is used to call methods or access attributes of the superclass.
Method Overriding:
Providing a specific implementation for a method that is already defined in the superclass.
Method Overloading:
Defining multiple methods in the same class with the same name but different parameters.
Abstract Class:
A class that cannot be instantiated and may contain abstract methods. It is meant to be subclassed.
Encapsulation:
Bundling of data (attributes) and methods that operate on the data within a single unit (class). It restricts direct access to some of an object’s components.
Composition:
A relationship between classes where one class contains an object of another class. It represents a “whole-part” relationship.
Aggregation:
A form of association where one class contains an object of another class. It represents a weaker relationship compared to composition.
Abstract Method:
A method without a body (implementation) defined in an abstract class or interface. Subclasses provide the implementation.
Final Class:
A class that cannot be subclassed. It is marked as final using the “final” keyword.
Final Method:
A method that cannot be overridden by subclasses. It is marked as final using the “final” keyword.
Final Variable:
A variable whose value cannot be changed after initialization. It is marked as final using the “final” keyword.
Static Method:
A method that belongs to the class rather than instances of the class. It can be called without creating an object.
Static Variable:
A variable that belongs to the class rather than instances of the class. It is shared among all instances.
Instance Variable:
A variable that belongs to an instance of a class. Each instance has its own copy.
Class Variable:
A variable that belongs to the class rather than instances of the class. It is shared among all instances.
Abstract Class:
A class that cannot be instantiated and may contain abstract methods. It is meant to be subclassed.
Abstract Method:
A method without a body (implementation) defined in an abstract class or interface. Subclasses provide the implementation.
Override Annotation:
An annotation used in Java to indicate that a method is intended to override a method in a superclass.
Protected Access Modifier:
Access modifier that allows access within the same package and by subclasses, but not outside the package.
Public Access Modifier:
Access modifier that allows unrestricted access to the class, its attributes, and methods.
Private Access Modifier:
Access modifier that restricts access to the class, its attributes, and methods only within the same class.
Default (Package-Private) Access Modifier:
Access modifier that allows access within the same package but not outside the package. It is the default access level.
Getter Method:
A method used to retrieve the value of a private attribute. It follows the naming convention “getVariableName.”
Setter Method:
A method used to set the value of a private attribute. It follows the naming convention “setVariableName.”
Dynamic Binding:
The process of linking a method call to its implementation at runtime. It enables polymorphism.
Object-Oriented Programming (OOP):
A programming paradigm based on the concept of objects, which represent real-world entities and have state and behavior.
