Classes and Objects in C++

Fundamental Concepts

A class is a blueprint that defines the characteristics and behaviors of objects. It represents an abstract concept that encapsulates data and functionality.

An object is a concrete instance created from a class definition. Objects possess the properties and capabilities defined by their class.

Class Components

Classes consist of two primary components:

• Attributes (member variables/data members): These represent the data characteristics of objects, typically described as nouns (e.g., height, type, model).
• Methods (member functions): These define the actions objects can perform, usually expressed as verbs (e.g., learn, calculate, display).

Consider a "SmartDevice" class example with the following specificatinos:

Attributes: manufacturer, device_type, battery_capacity

Methods: play_media(), execute_app(), connect_network()

#include <iostream>
#include <string>

using namespace std;

class SmartDevice {
public:
    string manufacturer;
    string device_type;
    int battery_capacity;

    void play_media() {
        cout << "Playing media content" << endl;
    }

    void execute_app() {
        cout << "Executing application" << endl;
    }

    void connect_network() {
        cout << "Establishing network connection" << endl;
    }
};

Object Instantiation

Objects can be created in two ways:

• Stack allocation: Objects created on the stack have automatic storage duration and are destroyed when they go out of scope.

int main() {
    // Create stack-allocated object
    SmartDevice my_device;
    
    // Set attribute values
    my_device.manufacturer = "TechCorp";
    my_device.device_type = "Tablet";
    my_device.battery_capacity = 5000;
    
    // Access attribute values
    cout << my_device.manufacturer << endl;
    cout << my_device.device_type << endl;
    cout << my_device.battery_capacity << endl;
    
    // Invoke member functions
    my_device.connect_network();
    my_device.play_media();
    my_device.execute_app();

    return 0;
}