How to Use extern in C ++How to Call Parent Class Function from Derived Class Function in C?

Below is an example of calling the parent class function from the derived class function.

Example

#include <bits/stdc++.h>
using namespace std;
class p1　{
　　　public:
　　　void first() {
　　　　　　cout << "\nThe parent class p1　function is called.";
　　　}
};
class d1　: public p1　{
　　　public:
　　　void first() {
　　　　　　cout << "The derived class d1　function is called.";
　　　　　　p1::first();
　　　}
};
int main() {
　　　d1　d;
　　　d.first();
　　　return 0;
}

Output Result

The derived class d1　function is called.
The parent class p1　function is called.

In the above program, the parent class p is created1and defines the function first() within it.

class p1　{
　　　public:
　　　void first() {
　　　　　　cout << "\nThe parent class p1　function is called.";
　　　}
};

Create a derived class that inherits from the parent class p1and overload the parent class function first().

class d1　: public p1　{
　　　public:
　　　void first() {
　　　　　　cout << "The derived class d1　function is called.";
　　　　　　p1::first();
　　　}
};

d1The function of the class is calling p1The function of the class.

p1::first();