C++ Inheritance

Inheritance is one of the core concepts of Object-Oriented Programming (OOP). It allows a class (called the child or derived class) to acquire properties and behaviors (data members and member functions) from another class (called the parent or base class).

1. Single Inheritance

#include <iostream>
using namespace std;

class A {
public:
  void showA() {
    cout << "Class A" << endl;
  }
};

class B : public A {
public:
  void showB() {
    cout << "Class B" << endl;
  }
};

int main() {
  B obj;
  obj.showA();
  obj.showB();
  return 0;
}

Output: Class A Class B

Explanation: Class B inherits Class A, so it can use both showA and showB.

2. Multilevel Inheritance

#include <iostream>
using namespace std;

class A {
public:
  void showA() {
    cout << "A" << endl;
  }
};
class B : public A {
public:
  void showB() {
    cout << "B" << endl;
  }
};
class C : public B {
public:
  void showC() {
    cout << "C" << endl;
  }
};

int main() {
  C obj;
  obj.showA();
  obj.showB();
  obj.showC();
  return 0;
}

Output: A B C

Explanation: C inherits B, B inherits A. So C has access to all three levels.

3. Multiple Inheritance

#include <iostream>
using namespace std;

class A {
public:
  void showA() {
    cout << "A" << endl;
  }
};
class B {
public:
  void showB() {
    cout << "B" << endl;
  }
};
class C : public A, public B {
public:
  void showC() {
    cout << "C" << endl;
  }
};

int main() {
  C obj;
  obj.showA();
  obj.showB();
  obj.showC();
  return 0;
}

Output: A B C

Explanation: C inherits both A and B directly.

4. Hierarchical Inheritance

#include <iostream>
using namespace std;

class Parent {
public:
  void showParent() {
    cout << "Parent" << endl;
  }
};
class Child1 : public Parent {
public:
  void showChild1() {
    cout << "Child1" << endl;
  }
};
class Child2 : public Parent {
public:
  void showChild2() {
    cout << "Child2" << endl;
  }
};

int main() {
  Child1 c1;
  Child2 c2;
  c1.showParent();
  c1.showChild1();
  c2.showParent();
  c2.showChild2();
  return 0;
}

Output: Parent Child1 Parent Child2

Explanation: Both Child1 and Child2 inherit from Parent.

5. Hybrid Inheritance (Simulated)

#include <iostream>
using namespace std;

class A {
public:
  void showA() {
    cout << "A" << endl;
  }
};
class B : public A {
public:
  void showB() {
    cout << "B" << endl;
  }
};
class C : public A {
public:
  void showC() {
    cout << "C" << endl;
  }
};
class D : public B, public C {
public:
  void showD() {
    cout << "D" << endl;
  }
};

int main() {
  D obj;
  obj.showB();
  obj.showC();
  obj.showD();
  return 0;
}

Output: B C D

Explanation: D inherits B and C; both derived from A. This simulates hybrid inheritance.

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