Inheritance

Inheritance allows a class to derive features (attributes and methods) from another class. This creates a "Parent-Child" relationship.

1. Key Terminology

• Base Class (Parent): The class whose features are inherited.

• Derived Class (Child): The class that inherits from the Base class.

• Reusability: Instead of rewriting code for similar objects, the Child class automatically gets everything the Parent has.

2. The "Is-A" Relationship

Use inheritance when an object is a specialized version of another.

• A Car is a Vehicle.

• A Manager is an Employee.

Code Example: Vehicle System

In this example, the Car class inherits from Vehicle. It gains the brand and honk() method without us having to type them again.

#include <iostream>
#include <string>
using namespace std;

// Base Class (Parent)
class Vehicle {
public:
    string brand = "Ford";
    
    void honk() {
        cout << "Beep! Beep!" << endl;
    }
};

// Derived Class (Child)
// Syntax: class Child : public Parent
class Car : public Vehicle {
public:
    string modelName = "Mustang";
};

int main() {
    Car myCar;

    // Accessing Parent members through the Child object
    myCar.honk(); 
    
    cout << "Brand: " << myCar.brand << endl;
    cout << "Model: " << myCar.modelName << endl;

    return 0;
}

3. Access Levels in Inheritance

• public members: Stay public in the child.

• private members: Are not accessible by the child class.

• protected members: A special middle ground—hidden from the outside world, but accessible to child classes.