CPP Tutorial

Inheritance in C++

Inheritance allows a class (called the derived class) to inherit properties and behaviors (data members and member functions) from another class (called the base class).

Why use inheritance?

• Reuse code without rewriting it.
• Create hierarchical relationships between classes.
• Enable polymorphism (different behaviors via base pointers).

Syntax of Inheritance:

class DerivedClass : access_specifier BaseClass {
  // body of derived class
};
  

access_specifier can be public, private, or protected, affecting the visibility of base members in derived class.

Example of Public Inheritance:

#include <iostream>
using namespace std;

class Animal {
  public:
    void eat() {
      cout << "Eating..." << endl;
    }
};

class Dog : public Animal {
  public:
    void bark() {
      cout << "Barking..." << endl;
    }
};

int main() {
  Dog myDog;
  myDog.eat();   // Inherited from Animal
  myDog.bark();  // Defined in Dog

  return 0;
}
  

🖨️ Output:

🔍 Explanation:

• Dog inherits the eat() method from Animal.
• Dog has its own method bark().
• So, myDog can call both eat() and bark().

Access Specifiers in Inheritance:

When inheriting, the base class members' accessibility can change depending on the access specifier:

• public inheritance: public members stay public, protected stay protected, private members remain inaccessible.
• protected inheritance: public and protected members become protected in derived class.
• private inheritance: public and protected members become private in derived class.

🎓 Summary

• Inheritance helps reuse code and create class hierarchies.
• Use public inheritance most often for “is-a” relationships.
• Access specifiers in inheritance control visibility of base class members in derived class.