OOPs Concepts In C++
Knowing a number of related core ideas is necessary to comprehend object-oriented programming (OOP) in C++, which aims to improve program organization, reusability, and maintainability. Generic, procedural, and object-oriented programming are all supported by the C++ programming language.
Objects
- An object-oriented system’s fundamental run-time entities are called objects.
- They are a collection of functions and data that show a person, a bank account, or a data table, among other real-world entities.
- Data and functions that act on that data are both contained in objects, which are the building blocks of an object-oriented software.
- In essence, an object is a variable of a type that the user defines. Car1 and Car2 might be objects of a Car class, for example, with distinct capacities (such as “to run” and “to brake”) and characteristics (such as date of construction, capacity, and chassis number).
Classes
- An object’s blueprint or template is called a class. It outlines what capabilities (member functions/methods) and attributes (data members) those kinds of objects will have.
- Grouping related data pieces using the term “struct” is a basic method. C++’s only technical difference between structs and classes is that struct members are public and class elements are private. Structs are often used to represent “Plain Old Data” (POD) classes with no user-defined constructors or in-class initializers and only public data members.
- Definition of a class (or struct) provides a blueprint but doesn’t allocate memory. That class’s variable must be declared to create an object.
- Behaviour classes let you define your own sorts.
Encapsulation (Data Abstraction / Data Hiding)
- Encapsulation groups data and methods into a class.
- It protects the data from outsiders so only class-wrapped functions can access it. These features offer the data a regulated interface.
- The goal of data abstraction in programming is to isolate a class’s implementation how the data is kept and how methods are implemented from its interface, or what activities users can do. The code that utilizes the class remains unaffected by changes made to the implementation details because to this separation.
- This abstraction is enforced by the use of access labels such as private and public in C++. Data concealing is made easier by the fact that C++ classes are private by default.
Inheritance
- In programming, inheritance creates a derived class from a base class.
- Derived classes inherit basic data and functions. Then, it can incorporate its own special qualities and powers.
- Inheritance creates a hierarchy of classes, usually starting with a base class.
- Code reuse is one of inheritance’s main benefits. New classes can be derived from a tested base class to adapt it to various scenarios without changing it.
- “Is A” relationships with base classes are typically embodied by derived classes (e.g., a “car” is a “vehicle”).
- Additionally, multiple inheritance is supported in C++, allowing a class to inherit attributes from two or more base classes.
Polymorphism
- Taking its name from a Greek term that means “many forms,” polymorphism is a fundamental concept in OOP.
- “One interface, multiple methods” is a feature that defines it. This means that a single interface can govern a generic class of actions, with object type determining execution.
- Virtual functions are the fundamental polymorphism mechanism in C++.
- Dynamic binding, also known as late binding, delays the choice of which virtual function to execute until run time when calling the function with a base-class type pointer or reference.
- The fundamental building block of C++’s polymorphism support is the ability for a reference or pointer’s static type known at compile time to differ from its dynamic type, or the actual object type at runtime.
Pointers to Objects
- Pointers store memory addresses.
- Access members of a structure or class object with the arrow operator (->).
- Member functions can use this unique object pointer.
Operator Overloading
- Operator overloading lets you change the meaning of most C++ operators on user-defined classes.
- This feature lets objects be used naturally in expressions, like built-in data types, making programs easier to write and read.
- Overloading +, for instance, adds two Sales_item instances, and using << and >> allows you to perform custom input/output operations with your classes.
- When defining these custom functions, the operator keyword is utilised. Although strong, not every operator can handle too much.
These ideas create the C++ object-oriented paradigm, which helps programmers envisage real-world difficulties and manage large software systems.