Introduction to Classes and Objects

Snippet

Introduction to Classes and Objects

Classes are blueprints for creating objects in C++. A class groups related data (variables) and functions (methods) together. In this example, we define a Dog class with name and age attributes, plus bark() and birthday() methods. The main() function creates an instance (object) of Dog called myDog and interacts with it using the dot operator.

snippet.cpp

cpp

class Dog {
public:
    std::string name;
    int age;
    
    void bark() {
        std::cout << name << " says: Woof! Woof!" << std::endl;
    }
    
    void birthday() {
        age++;
    }
};
 
int main() {
    Dog myDog;
    myDog.name = "Buddy";
    myDog.age = 3;
    myDog.bark();
    myDog.birthday();
    return 0;
}

Breakdown

class Dog {

Declares a new class named Dog starting the class definition

public:

Access specifier allowing members to be accessed from outside the class

std::string name;

Member variable storing the dog's name

int age;

Member variable storing the dog's age

void bark() { ... }

Member function that outputs a bark message

Dog myDog;

Creates an object (instance) of the Dog class

myDog.name = "Buddy";

Accesses and sets the name member using the dot operator

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