C++ Multilevel Inheritance

Multilevel Inheritance in C++ is the process of deriving a class from another derived class. When one class inherits another class it is further inherited by another class. It is known as multi-level inheritance.

For example, if we take Grandfather as a base class then Father is the derived class that has features of Grandfather and then Child is the also derived class that is derived from the sub-class Father which inherits all the features of Father.

Example:

Base class-> Wood, Intermediate class-> furniture, subclass-> table

Block Diagram of Multilevel Inheritance

As shown in the diagram class B inherits property from class A and class C inherits property from class B.

Syntax:

class A // base class
{
    ...........
};
class B : access_specifier A // derived class
{
    ...........
} ;
class C : access_specifier B // derived from derived class B
{
    ...........
} ;

Know more about Access Modifiers in C++.

Example:

C++

// C++ program to implement
// Multilevel Inheritance
#include <bits/stdc++.h>
using namespace std;

// single base class
class A {
public:
    int a;
    void get_A_data()
    {
        cout << "Enter value of a: ";
        cin >> a;
    }
};

// derived class from base class
class B : public A {
public:
    int b;
    void get_B_data()
    {
        cout << "Enter value of b: ";
        cin >> b;
    }
};

// derived from class derive1
class C : public B {
private:
    int c;

public:
    void get_C_data()
    {
        cout << "Enter value of c: ";
        cin >> c;
    }

    // function to print sum
    void sum()
    {
        int ans = a + b + c;
        cout << "sum: " << ans;
    }
};
int main()
{
    // object of sub class
    C obj;

    obj.get_A_data();
    obj.get_B_data();
    obj.get_C_data();
    obj.sum();
    return 0;
}

Output:

Enter value of a: 4

Enter value of b: 5

Enter value of c: 9

sum: 18