General Study Notes Overview

Encapsulation is a core OOP principle that involves bundling data (variables) and methods (functions) that operate on the data together into a single unit called a class. It restricts direct access to some components of the object to protect data integrity and security.

Access specifiers in C++ control the visibility of class members (variables and methods) from outside the class. There are three main access specifiers: public, private, and protected.

Private members are accessible only within the class or by friend functions. They're typically used for data members and implementation details.

Public members are accessible from anywhere, both inside and outside the class. They're typically used for functions that need to be accessed by other parts of the program, such as the class's interface methods.

Protected members are accessible within the class and in derived classes, but not from outside the class. They're typically used in base classes to allow derived classes to access specific members while preventing external access.

A class serves as a blueprint or template for creating objects. It defines the structure and behavior (data members and member functions) that objects of the class will have.

An object is an instance of a class. It occupies memory and represents a real-world entity. Each object has its own copy of the class's data members, and objects interact by sending messages (method calls).

Constructors are special member functions called automatically whenever an object of a class is created. They initialize the data members of the class.

A copy constructor is a special type of constructor that creates a new object as a copy of an existing object. It's invoked when an object is initialized from another object of the same class, passed by value to a function, or returned by value from a function. A shallow copy copies the values of all member variables, while a deep copy requires a custom copy constructor to handle dynamically allocated memory.

A destructor is a special member function that is called automatically when an object is destroyed. It frees up resources allocated to the object, such as memory.

Message passing is a mechanism in OOP where objects communicate with each other by invoking methods. An object sends a message (method call) to another object, requesting it to perform a specific action.

Dynamic binding (late binding) is the process where the method to be invoked is determined at runtime, not at compile time. It allows objects of derived classes to override methods of their base class and execute the appropriate version.

Object-oriented programming (OOP) is a programming paradigm that focuses on objects that encapsulate both data and methods, improving data security, modularity, code reusability, and real-world problem representation.

Structured programming is procedural-based and focuses on functions and procedures to operate on data. OOP is object-based and focuses on objects encapsulating both data and methods.

Mul ple inheritance occurs when a class inherits from two or more base classes. This can lead to ambiguity if both base classes have methods with the same name.

Overloading occurs when two or more functions in the same scope have the same name but differ in the number or type of their parameters. It's resolved at compile time.

Overriding occurs when a subclass provides its own implementation of a function already defined in its superclass. The function signature in the derived class must be the same as in the base class, and it's resolved at runtime.

Inheritance is a core OOP concept where a class (derived class) acquires properties and behaviors from another class (base class). It enables code reusability and better organization of complex systems.

Aggrega on is an OOP concept that represents a "has-a" relationship between objects, where one object is a part of another but can exist independently. The aggregated object can exist without the container object.

Composi on is a strong form of association where the contained object cannot exist independently of the container object. If the container is destroyed, the contained object is destroyed as well.

The "this" keyword is a special pointer that is automatically passed to all non-static member functions of a class. It points to the current instance of the class (the object that invoked the member function). It can be used to refer to the current object, access member variables and functions, and check for self-assignment.

File streams in C++ are objects used to handle reading from and writing to files. They provide an abstraction that allows the program to read and write to files like standard input/output devices (console).

An ifstream object is used to read data from a file. It provides functions to open, close, and read data.

An ofstream object is used to write data to a file. It provides functions to open, close, and write data.

A fstream object combines the features of ifstream and ofstream, allowing both reading from and writing to the same file.

Operator overloading allows you to define custom behavior for operators (like +,-, *, etc.) when they are applied to objects of user-defined classes. It makes classes more intuitive and easier to use.

Ambiguity in multiple inheritance arises when a derived class inherits the same member (function or variable) from more than one base class. The compiler doesn't know which base class member to use.

Virtual inheritance eliminates ambiguity by ensuring that the derived class has a single copy of the common base class. It's achieved by using the virtual keyword.

Run- time polymorphism (dynamic polymorphism), enabled by using the virtual keyword, dynamically selects the appropriate method based on the actual object type at runtime. It enables flexibility, code reusability, and dynamic behavior in programs.

In C++, garbage collection is the process of automatically reclaiming unused memory to ensure efficient memory management. While some languages have built-in garbage collection, C++ relies on manual memory management through new, delete, and smart pointers.

An abstract class is a class that cannot be instantiated (created) directly and typically contains one or more pure virtual functions, declared with = 0. Abstract classes define a common interface for derived classes, enforcing that certain methods must be implemented.

A pure virtual function in an abstract class is a function that is not implemented in the abstract class itself. It must be overridden by derived classes. It is declared using the = 0 syntax.

RAII (Resource Acquisition Is Initialization) is a technique that encapsulates resource management into objects. When an object is created, it acquires necessary resources and when the object is destroyed, it releases those resources.

A nested if-else statement is used for complex decision-making with multiple conditions. A switch statement is used for simpler, multi-way branching based on a single variable or expression, making it easier to read and maintain.