How to call a base class function from a derived class function

Overview

In this shot, we'll learn how to call a base class function from a derived class function in C++.

Syntax

We can call a base class function from a derived class using the following syntax:

baseClassName :: functionName();
Syntax

Now, let's see some examples.

The base class

Let's first create a base class.

class base {

    public:

    void display () {

        cout << "Function of base class" << endl;

    }

}

Explanation

  • Line 1: We define a class base.
  • Lines 3–5 : We create a function display().

The derived class

Let's create a derived class by extending the base class.

class derived: public base {

    public:

    void display () {

        cout << "Function of derived class" << endl;



        // calling base class function

        base :: display();

    }

}

Explanation

  • Line 1: We define a class derived by extending the class base.
  • Line 3–8: We override the base class function display().
  • Line 7: We call the base class function display() from the derived class.

Example

#include <bits/stdc++.h>
using namespace std;
class base {
    public:
    void display () {
        cout << "Function of base class" << endl;
    }
};
class derived: public base {
    public:
    void display () {
        cout << "Function of derived class" << endl;
        // calling base class function
        base :: display();
    }
};
int main() {
    // create object of derived class 
    derived d;
    d.display();
    return 0;
}

Explanation

  • Line 1: We import the bits/stdc++.h library.
  • Line 4–19: We create a base class and a derived class.
  • Line 21–26: Inside the main() function, we create an object of the derived class and call its display() function.
  • On calling the display() function of the derived class:
    • It prints "Function of derived class" on the console.
    • It calls the display() function of the base class.
    • It prints "Function of base class" on the console.

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