What Is A Class In Programming Explained Simply

What Is A Class In Programming? Classes are the core building blocks of object-oriented programming, defining blueprints for creating objects with specific attributes and behaviors. At WHAT.EDU.VN, we break down this fundamental concept in a clear, accessible way, offering a free and easy path to understanding. Explore class definitions, object creation, and the power of abstraction with us.

1. Understanding the Basics of Classes

Classes form the bedrock of object-oriented programming (OOP). They serve as templates for creating objects, which are instances of the class. Imagine a class as a blueprint for a house. The blueprint defines the structure and features of the house, but it’s not the house itself. Similarly, a class defines the characteristics and behaviors of an object, but it doesn’t represent an actual object in memory until it is instantiated.

1.1. Definition of a Class

A class is a user-defined data type that encapsulates data (attributes) and the code that operates on that data (methods). Attributes represent the state of an object, while methods define its behavior. For example, a Dog class might have attributes like breed, age, and color, and methods like bark(), wagTail(), and eat().

1.2. Key Components of a Class

Classes consist of two primary components:

• Attributes (Data Members/Fields): These are variables that store data related to the class. They define the characteristics or properties of objects created from the class.
• Methods (Member Functions): These are functions that define the actions or behaviors that objects of the class can perform. They operate on the attributes of the object.

1.3. Analogy: The Blueprint

Think of a class as a blueprint for a house:

• The blueprint is the class.
• Each house built from the blueprint is an object.
• The features of the house (number of rooms, color, materials) are the attributes.
• The actions you can perform in the house (open the door, turn on the lights) are the methods.

1.4. How Classes Relate to Objects

A class is a template, while an object is an instance of that template. Multiple objects can be created from a single class, each with its own unique set of attribute values. Just as you can build multiple houses from the same blueprint, you can create multiple objects from the same class.

1.5. Benefits of Using Classes

• Modularity: Classes allow you to break down complex problems into smaller, more manageable units.
• Reusability: Once a class is defined, it can be used to create multiple objects, reducing code duplication.
• Encapsulation: Classes protect data by bundling it with the methods that operate on it, preventing unauthorized access.
• Abstraction: Classes hide the internal implementation details of an object, exposing only the necessary interface to the user.
• Inheritance: Classes can inherit properties and methods from other classes, promoting code reuse and creating a hierarchy of objects.
• Polymorphism: Objects of different classes can respond to the same method call in different ways, providing flexibility and extensibility.

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2. Declaring and Defining Classes

The declaration and definition of a class involves specifying its attributes and methods. Different programming languages have different syntax for class declaration, but the underlying concepts are similar.

2.1. Syntax in Different Languages

Here’s a comparison of class declaration syntax in some popular programming languages:

Language	Syntax
C++	class ClassName { public: // Attributes and methods };
Java	class ClassName { // Attributes and methods }
Python	class ClassName: // Attributes and methods
C#	class ClassName { // Attributes and methods }
JavaScript	class ClassName { constructor() { // Attributes } // Methods }
PHP	class ClassName { // Attributes and methods }
Swift	class ClassName { // Attributes and methods }
Kotlin	class ClassName { // Attributes and methods }
Ruby	class ClassName // Attributes and methods end
Go	type ClassName struct { // Attributes } func (c ClassName) MethodName() { // Method } (Note: Go uses structs with methods for similar functionality to classes.)

2.2. Example Class Declaration (C++)

 class Dog {
 public:
  string breed;
  int age;
  string color;

  void bark() {
  cout << "Woof!" << endl;
  }

  void wagTail() {
  cout << "Wagging tail..." << endl;
  }
 };

2.3. Access Modifiers

Access modifiers control the visibility of class members (attributes and methods). They determine which parts of the code can access and modify the members of a class. Common access modifiers include:

• Public: Members are accessible from anywhere.
• Private: Members are only accessible from within the class.
• Protected: Members are accessible from within the class and its subclasses (inherited classes).

2.3.1. Public Access Modifier

Members declared as public are accessible from any part of the program. This means that you can access and modify public attributes and call public methods from outside the class.

2.3.2. Private Access Modifier

Members declared as private are only accessible from within the class. This means that you cannot directly access or modify private attributes or call private methods from outside the class. Private members are used to encapsulate data and hide the internal implementation details of the class.

2.3.3. Protected Access Modifier

Members declared as protected are accessible from within the class and its subclasses (inherited classes). This is useful when you want to allow subclasses to access certain members of the base class, but prevent access from other parts of the program.

Here’s an example to illustrate the use of access modifiers in C++:

 class Animal {
 private:
  string name; // Only accessible within the Animal class

 protected:
  int age; // Accessible within the Animal class and its subclasses

 public:
  string breed; // Accessible from anywhere

  void setName(string animalName) {
  name = animalName; // Correctly accessing private member within the class
  }

  string getName() const {
  return name; // Correctly accessing private member within the class
  }

  void displayAge() {
  cout << "Age: " << age << endl; // Correctly accessing protected member within the class
  }
 };

 class Dog : public Animal {
 public:
  void displayDogAge() {
  age = 5; // Correctly accessing protected member from the derived class
  cout << "Dog Age: " << age << endl;
  }
 };

 int main() {
  Animal animal;
  Dog dog;

  // Public member can be accessed from anywhere
  animal.breed = "Unknown";
  cout << "Animal Breed: " << animal.breed << endl;

  // Trying to access private member outside the class will result in an error
  // animal.name = "Generic Animal"; // This line would cause an error

  // Using public method to set private member
  animal.setName("Generic Animal");
  cout << "Animal Name: " << animal.getName() << endl;

  // Protected member can be accessed by the derived class
  dog.displayDogAge();

  return 0;
 }

2.4. Constructor and Destructor

• Constructor: A special method that is automatically called when an object of the class is created. It is used to initialize the attributes of the object.
• Destructor: A special method that is automatically called when an object of the class is destroyed. It is used to release any resources held by the object.

2.4.1. Constructor

A constructor is a special method within a class that is automatically called when an object of the class is created. Its primary purpose is to initialize the attributes of the object, ensuring that the object is in a valid and usable state from the moment it is created.

Key characteristics of constructors include:

• Name: A constructor has the same name as the class.
• No Return Type: Constructors do not have a return type, not even void.
• Purpose: To initialize the object’s state.
• Automatic Invocation: Called automatically when an object is created using new (in languages like Java, C++) or directly (in languages like Python).
• Multiple Constructors: A class can have multiple constructors with different parameters (method overloading), allowing objects to be initialized in different ways.

Here is a simple example of a constructor in C++:

 #include <iostream>
 #include <string>

 class Dog {
 public:
  // Attributes
  std::string breed;
  int age;

  // Default Constructor
  Dog() {
  breed = "Unknown";
  age = 0;
  std::cout << "Default constructor called." << std::endl;
  }

  // Parameterized Constructor
  Dog(std::string dogBreed, int dogAge) {
  breed = dogBreed;
  age = dogAge;
  std::cout << "Parameterized constructor called." << std::endl;
  }

  // Method to display dog's information
  void displayInfo() {
  std::cout << "Breed: " << breed << ", Age: " << age << " years" << std::endl;
  }
 };

 int main() {
  // Creating objects using different constructors
  Dog dog1; // Calls the default constructor
  dog1.displayInfo();

  Dog dog2("Golden Retriever", 3); // Calls the parameterized constructor
  dog2.displayInfo();

  return 0;
 }

2.4.2. Destructor

A destructor is a special method within a class that is automatically called when an object of the class is no longer needed and is being destroyed. Its primary purpose is to release any resources (such as memory, file handles, network connections, etc.) that the object has acquired during its lifetime. This ensures that the resources are properly cleaned up, preventing memory leaks and other issues.

Key characteristics of destructors include:

• Name: A destructor has the same name as the class, but is prefixed with a tilde ~.
• No Parameters: Destructors do not accept any parameters.
• No Return Type: Destructors do not have a return type, not even void.
• Purpose: To release resources held by the object.
• Automatic Invocation: Called automatically when an object goes out of scope or is explicitly deleted using delete (in languages like C++).
• Single Destructor: A class can have only one destructor.

Here is a simple example of a destructor in C++:

 #include <iostream>

 class MyClass {
 public:
  // Constructor
  MyClass() {
  data = new int[10]; // Allocate some memory
  std::cout << "Constructor called: Memory allocated." << std::endl;
  }

  // Destructor
  ~MyClass() {
  delete[] data; // Release the memory
  std::cout << "Destructor called: Memory released." << std::endl;
  }

 private:
  int* data;
 };

 int main() {
  MyClass obj; // Create an object
  // When obj goes out of scope, the destructor ~MyClass() is automatically called

  return 0;
 }

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3. Creating Objects

Creating objects from a class involves instantiating the class, which means allocating memory for the object and initializing its attributes.

3.1. Instantiation

Instantiation is the process of creating an object from a class. It involves allocating memory for the object and initializing its attributes. The syntax for instantiation varies depending on the programming language.

3.2. Syntax in Different Languages

Here’s a comparison of object instantiation syntax in some popular programming languages:

Language	Syntax
C++	ClassName objectName; or ClassName* objectName = new ClassName();
Java	ClassName objectName = new ClassName();
Python	objectName = ClassName()
C#	ClassName objectName = new ClassName();
JavaScript	const objectName = new ClassName();
PHP	$objectName = new ClassName();
Swift	let objectName = ClassName()
Kotlin	val objectName = ClassName()
Ruby	objectName = ClassName.new
Go	objectName := ClassName{} (Note: Go uses structs with methods for similar functionality to classes, and instantiation is done using composite literals.)

3.3. Example Object Creation (C++)

 Dog myDog; // Creates an object of the Dog class
 myDog.breed = "Golden Retriever";
 myDog.age = 3;
 myDog.color = "Golden";

 cout << "My dog is a " << myDog.breed << " who is " << myDog.age << " years old and has " << myDog.color << " fur." << endl;

3.4. Accessing Attributes and Methods

Once an object is created, you can access its attributes and methods using the dot operator (.). The syntax is objectName.attributeName for attributes and objectName.methodName() for methods.

3.5. Multiple Objects

You can create multiple objects from the same class, each with its own unique set of attribute values. Each object is independent of the others and has its own memory space.

 Dog dog1;
 dog1.breed = "Labrador";
 dog1.age = 5;
 dog1.color = "Black";

 Dog dog2;
 dog2.breed = "Poodle";
 dog2.age = 2;
 dog2.color = "White";

 cout << "Dog 1 is a " << dog1.breed << " and Dog 2 is a " << dog2.breed << "." << endl;

3.6. Real-World Examples

Classes and objects are used extensively in real-world programming to model various entities and concepts. Here are some examples:

• GUI Applications: Classes can represent windows, buttons, text boxes, and other UI elements.
• Game Development: Classes can represent characters, enemies, items, and other game objects.
• Database Management: Classes can represent tables, records, and fields in a database.
• Web Development: Classes can represent users, products, orders, and other entities in an e-commerce application.
• Data Analysis: Classes can represent datasets, statistical models, and visualizations.

3.7. Practical Exercises

To solidify your understanding of classes and objects, try these practical exercises:

• Create a Rectangle class with attributes width and height, and methods getArea() and getPerimeter().
• Create a Circle class with attribute radius and methods getArea() and getCircumference().
• Create a Student class with attributes name, age, and grade, and methods getName(), getAge(), and getGrade().

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4. Benefits of Object-Oriented Programming

Object-oriented programming offers several advantages over procedural programming, including modularity, reusability, encapsulation, abstraction, inheritance, and polymorphism.

4.1. Modularity and Organization

OOP promotes modularity by breaking down complex problems into smaller, more manageable units called classes. Each class represents a distinct entity with its own attributes and behaviors. This modular structure makes it easier to understand, maintain, and debug code.

4.2. Code Reusability

OOP facilitates code reusability through inheritance and composition. Inheritance allows a class to inherit properties and methods from another class, reducing code duplication and promoting a hierarchical structure. Composition allows a class to contain objects of other classes, reusing their functionality.

4.3. Encapsulation and Data Hiding

OOP enforces encapsulation by bundling data (attributes) and the code that operates on that data (methods) within a class. This protects the data from unauthorized access and modification. Access modifiers (public, private, protected) control the visibility of class members, allowing you to hide internal implementation details and expose only the necessary interface to the user.

4.4. Abstraction and Simplification

OOP supports abstraction by hiding the internal complexity of an object and exposing only the essential features to the user. This simplifies the interaction with objects and makes the code more user-friendly. Abstract classes and interfaces define a common interface for a group of related classes, allowing you to treat them as a single unit.

4.5. Inheritance and Polymorphism

OOP enables inheritance, which allows a class to inherit properties and methods from another class. This promotes code reuse and creates a hierarchy of objects. Polymorphism allows objects of different classes to respond to the same method call in different ways, providing flexibility and extensibility.

4.5.1. Inheritance

Inheritance is a fundamental concept in object-oriented programming (OOP) that allows a class (called a subclass or derived class) to inherit properties and behaviors from another class (called a superclass or base class). It promotes code reuse and establishes a hierarchical relationship between classes.

Key aspects of inheritance include:

• Code Reusability: Subclasses inherit attributes and methods from their superclass, reducing code duplication.
• Extensibility: Subclasses can add new attributes and methods or override existing ones to extend or modify the behavior of the superclass.
• Hierarchical Structure: Inheritance creates a hierarchical structure of classes, representing “is-a” relationships (e.g., a Dog is-a Animal).
• Single and Multiple Inheritance: Some languages support single inheritance (a class can inherit from only one superclass), while others support multiple inheritance (a class can inherit from multiple superclasses).
• Types of Inheritance: Common types include single, multiple, multilevel, hierarchical, and hybrid inheritance, each with its own characteristics and use cases.

Here is a basic example of inheritance in C++:

 #include <iostream>
 #include <string>

 // Base class (Superclass)
 class Animal {
 public:
  // Attributes
  std::string name;

  // Constructor
  Animal(std::string animalName) : name(animalName) {}

  // Method to display animal's name
  void displayInfo() {
  std::cout << "Name: " << name << std::endl;
  }

  // Method for animal sound
  virtual void makeSound() {
  std::cout << "Generic animal sound" << std::endl;
  }
 };

 // Derived class (Subclass) inheriting from Animal
 class Dog : public Animal {
 public:
  // Constructor
  Dog(std::string dogName) : Animal(dogName) {}

  // Override makeSound method for Dog
  void makeSound() override {
  std::cout << "Woof!" << std::endl;
  }
 };

 int main() {
  // Create an Animal object
  Animal animal("Generic Animal");
  animal.displayInfo();
  animal.makeSound();

  // Create a Dog object
  Dog dog("Buddy");
  dog.displayInfo(); // Inherited from Animal
  dog.makeSound(); // Overrides the Animal's makeSound method

  return 0;
 }

4.5.2. Polymorphism

Polymorphism is another core concept in object-oriented programming (OOP) that allows objects of different classes to respond to the same method call in their own specific ways. It provides flexibility and extensibility in designing and implementing software systems.

Key aspects of polymorphism include:

• Method Overriding: Subclasses can override methods inherited from their superclass to provide their own implementation.
• Method Overloading: A class can have multiple methods with the same name but different parameters (number, type, or order).
• Dynamic Binding: The specific method to be called is determined at runtime based on the object’s actual type.
• Interface Implementation: Classes can implement interfaces, which define a set of methods that the class must implement.
• Generic Programming: Polymorphism is used extensively in generic programming, where code is written to work with objects of any type that supports a certain interface.

Here is an example to illustrate polymorphism in C++:

 #include <iostream>
 #include <string>

 // Base class (Superclass)
 class Animal {
 public:
  // Virtual function to allow derived classes to override it
  virtual void makeSound() {
  std::cout << "Generic animal sound" << std::endl;
  }
 };

 // Derived class 1 (Subclass)
 class Dog : public Animal {
 public:
  // Override makeSound method for Dog
  void makeSound() override {
  std::cout << "Woof!" << std::endl;
  }
 };

 // Derived class 2 (Subclass)
 class Cat : public Animal {
 public:
  // Override makeSound method for Cat
  void makeSound() override {
  std::cout << "Meow!" << std::endl;
  }
 };

 int main() {
  // Create objects of different classes
  Animal* animal1 = new Animal();
  Animal* animal2 = new Dog();
  Animal* animal3 = new Cat();

  // Call makeSound method on each object
  animal1->makeSound(); // Output: Generic animal sound
  animal2->makeSound(); // Output: Woof!
  animal3->makeSound(); // Output: Meow!

  // Clean up memory
  delete animal1;
  delete animal2;
  delete animal3;

  return 0;
 }

4.6. Software Development Lifecycle

OOP simplifies the software development lifecycle by providing a structured approach to designing, developing, testing, and maintaining software systems. It promotes modularity, reusability, and maintainability, reducing the overall cost and effort of software development.

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5. Practical Applications of Classes

Classes are used extensively in various domains to model real-world entities and concepts. Here are some examples:

5.1. Data Structures

Classes can be used to implement various data structures, such as linked lists, stacks, queues, trees, and graphs. Each data structure can be represented as a class with its own attributes and methods.

5.1.1. Linked Lists

A linked list is a linear data structure where elements are stored in nodes, and each node contains a data element and a pointer to the next node in the sequence. Linked lists can be used to implement dynamic arrays, stacks, queues, and other data structures.

Here is an example of a linked list class in C++:

 #include <iostream>

 // Definition of the Node structure
 struct Node {
  int data; // Data stored in the node
  Node* next; // Pointer to the next node
 };

 // Definition of the LinkedList class
 class LinkedList {
 private:
  Node* head; // Pointer to the first node in the list

 public:
  // Constructor to initialize an empty list
  LinkedList() {
  head = nullptr;
  }

  // Function to insert a new node at the end of the list
  void insert(int value) {
  Node* newNode = new Node; // Create a new node
  newNode->data = value; // Set the data of the new node
  newNode->next = nullptr; // The new node is the last node, so it points to nullptr

  if (head == nullptr) {
  // If the list is empty, the new node becomes the head
  head = newNode;
  } else {
  // If the list is not empty, find the last node and add the new node to it
  Node* temp = head;
  while (temp->next != nullptr) {
  temp = temp->next;
  }
  temp->next = newNode;
  }
  }

  // Function to display the elements of the list
  void display() {
  Node* temp = head; // Start from the head of the list
  while (temp != nullptr) {
  // Print the data of the current node
  std::cout << temp->data << " ";
  // Move to the next node
  temp = temp->next;
  }
  std::cout << std::endl;
  }
 };

 int main() {
  // Create a LinkedList object
  LinkedList myList;

  // Insert elements into the list
  myList.insert(10);
  myList.insert(20);
  myList.insert(30);

  // Display the elements of the list
  std::cout << "Linked List: ";
  myList.display();

  return 0;
 }

5.1.2. Stacks

A stack is a linear data structure that follows the Last-In-First-Out (LIFO) principle. Elements are added and removed from the top of the stack. Stacks are used in various applications, such as function call stacks, expression evaluation, and backtracking algorithms.

5.1.3. Queues

A queue is a linear data structure that follows the First-In-First-Out (FIFO) principle. Elements are added to the rear of the queue and removed from the front of the queue. Queues are used in various applications, such as task scheduling, message queues, and breadth-first search algorithms.

5.1.4. Trees

A tree is a hierarchical data structure that consists of nodes connected by edges. Each node contains a data element, and the edges represent the relationships between the nodes. Trees are used in various applications, such as file systems, decision trees, and search algorithms.

5.1.5. Graphs

A graph is a non-linear data structure that consists of nodes (vertices) connected by edges. Graphs are used to represent relationships between objects, such as social networks, transportation networks, and computer networks.

5.2. Graphical User Interfaces (GUIs)

Classes are used to represent GUI elements, such as windows, buttons, text boxes, and labels. Each GUI element can be represented as a class with its own attributes and methods.

5.3. Game Development

Classes are used extensively in game development to represent game objects, such as characters, enemies, items, and projectiles. Each game object can be represented as a class with its own attributes and methods.

5.4. Simulation and Modeling

Classes can be used to simulate and model real-world systems, such as traffic flow, weather patterns, and financial markets. Each entity in the system can be represented as a class with its own attributes and methods.

5.5. Web Development

Classes can be used to represent web pages, forms, and other web elements. Each web element can be represented as a class with its own attributes and methods.

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6. Advanced Class Concepts

Once you have a solid understanding of the basics of classes, you can explore more advanced concepts, such as inheritance, polymorphism, abstract classes, interfaces, and design patterns.

6.1. Inheritance and Polymorphism (Advanced)

Inheritance and polymorphism are two of the most powerful features of object-oriented programming. They allow you to create a hierarchy of classes and treat objects of different classes as a single unit.

6.1.1. Multiple Inheritance

Multiple inheritance is a feature in some object-oriented programming languages where a class can inherit from multiple base classes. This means the derived class inherits the attributes and methods of all its parent classes. However, multiple inheritance can introduce complexities such as the “diamond problem,” where ambiguity arises if two parent classes have a common ancestor.

Here is a simple example to illustrate multiple inheritance in C++:

 #include <iostream>
 #include <string>

 // Class 1: Person
 class Person {
 public:
  std::string name;
  void setName(std::string personName) {
  name = personName;
  }
  void displayPerson() {
  std::cout << "Name: " << name << std::endl;
  }
 };

 // Class 2: Employee
 class Employee {
 public:
  int employeeID;
  void setEmployeeID(int id) {
  employeeID = id;
  }
  void displayEmployee() {
  std::cout << "Employee ID: " << employeeID << std::endl;
  }
 };

 // Class 3: HybridEmployee inheriting from both Person and Employee
 class HybridEmployee : public Person, public Employee {
 public:
  std::string department;
  void setDepartment(std::string dept) {
  department = dept;
  }
  void displayHybridEmployee() {
  displayPerson();
  displayEmployee();
  std::cout << "Department: " << department << std::endl;
  }
 };

 int main() {
  HybridEmployee hybridEmp;
  hybridEmp.setName("John Doe");
  hybridEmp.setEmployeeID(12345);
  hybridEmp.setDepartment("Engineering");
  hybridEmp.displayHybridEmployee();

  return 0;
 }

6.1.2. Method Overriding

Method overriding occurs when a subclass provides a specific implementation for a method that is already defined in its superclass. The overridden method in the subclass has the same name, return type, and parameters as the method in the superclass. This allows the subclass to customize the behavior of inherited methods.

6.1.3. Abstract Classes

An abstract class is a class that cannot be instantiated directly. It serves as a blueprint for other classes and may contain abstract methods (methods without an implementation). Subclasses must provide concrete implementations for all abstract methods in the abstract class.

6.1.4. Interfaces

An interface is a contract that defines a set of methods that a class must implement. Interfaces do not contain any implementation details; they only specify the method signatures. A class can implement multiple interfaces, providing a flexible way to define the behavior of objects.

6.2. Design Patterns

Design patterns are reusable solutions to common programming problems. They represent best practices for designing and implementing software systems. Common design patterns include:

• Singleton: Ensures that a class has only one instance and provides a global point of access to it.
• Factory: Creates objects without specifying their concrete classes.
• Observer: Defines a one-to-many dependency between objects, so that when one object changes state, all its dependents are notified and updated automatically.
• Strategy: Defines a family of algorithms, encapsulates each one, and makes them interchangeable.
• Decorator: Adds responsibilities to an object dynamically.

6.3. SOLID Principles

The SOLID principles are a set of five design principles that promote maintainable, extensible, and testable code. They are:

• Single Responsibility Principle: A class should have only one reason to change.
• Open/Closed Principle: A class should be open for extension but closed for modification.
• Liskov Substitution Principle: Subtypes must be substitutable for their base types.
• Interface Segregation Principle: Clients should not be forced to depend on methods they do not use.
• Dependency Inversion Principle: High-level modules should not depend on low-level modules. Both should depend on abstractions.

6.4. Metaclasses

Metaclasses are classes that create other classes. They are used to customize the class creation process and add additional behavior to classes. Metaclasses are a powerful but advanced feature of object-oriented programming.

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7. Classes vs. Structs

In many programming languages, classes and structs are similar constructs that are used to define data structures. However, there are some key differences between them:

7.1. Default Access Modifier

In C++, the default access modifier for class members is private, while the default access modifier for struct members is public. This means that class members are not accessible from outside the class unless they are explicitly declared as public, while struct members are accessible from anywhere by default.

7.2. Inheritance

In C++, classes can inherit from other classes, while structs cannot inherit from classes. However, structs can inherit from other structs.

7.3. Usage

Classes are typically used to represent objects with both data and behavior, while structs are typically used to represent simple data structures. However, this is just a convention, and you can use classes and structs interchangeably in many cases.

7.4. Memory Layout

In general, the memory layout of classes and structs is the same. The attributes are stored in the order they are declared, and the methods are stored separately in a method table.

7.5. Key Differences Summary

Feature	Class	Struct
Default Access	private	public
Inheritance (C++)	Can inherit from classes and structs	Can only inherit from structs
Typical Usage	Objects with data and behavior	Simple data structures
Encapsulation Level	Higher, due to default private access	Lower, due to default public access
Object-Oriented	More commonly used in OOP scenarios	Often used for data storage and organization

Here is an example that demonstrates the differences between classes and structs in C++:

 #include <iostream>

 // Example of a struct
 struct Point {
  int x; // public by default
  int y; // public by default

  void display() {
  std::cout << "Point: (" << x << ", " << y << ")" << std::endl;
  }
 };

 // Example of a class
 class Rectangle {
 private: // private by default
  int width;
  int height;

 public:
  // Constructor
  Rectangle(int w, int h) : width(w), height(h) {}