A derived class constructor using base class constructor

[CroCo]

Is this example correct? This example from a book

Constructor of the Base Class

Person::Person(char* n="", char* nat="U.S.A", int s=1)
{
	name = n;
	nationality = nat;
	sex = s;
}

Constructor of the Derived Class (inherited from the base class)

Student(char* n, int s=0, char* i=""): 
      Person(n, s)

Why the initialized list of the base class constructor doesn't match the initialized list of the derived class constructor?
I know this book is a little bit old, I'm not sure if this wrong in VC++ 2010?

[pogrady]

Because there is a default value for nat, which is U.S.A (which is missing a period btw), so there is no reason to include it, but it should have been done anyway.

[cire]

Why the initialized list of the base class constructor doesn't match the initialized list of the derived class constructor?
I know this book is a little bit old, I'm not sure if this wrong in VC++ 2010?

The code is incorrect anywhere.

An argument must be supplied for nat since a value is supplied for s. One cannot skip arguments in the middle of a parameter list and expect default arguments to be supplied for it. Default values are only given to arguments not supplied at the end of a parameter list. If the Person constructor was changed to:

Person::Person(char*n="", int s=1, char* nat="U.S.A")

the derived class constructor would work. Leaving the base class the same and adjusting the derived class to supply the argument would also work.

[CroCo]

@pogrady
@cire
thank guys for your helping.

@cire
This is what I thought.

I have another question. Why this example doesn't work.

main file

#include "Person.h"
#include <iostream>
#include <string>
using namespace std;


int main()
{
	Person creator("Bjarne Stroustrup", "Denmark");
	cout << "The creator of C++ was ";
	creator.printName();
	cout << ", who was born in ";
	creator.printNationality();
	cout << ".\n";

	system("pause");
	return 0;
}

.cpp file for the Person Class

#include "Person.h"

Person::Person(char* n="", char* nat="U.S.A", int s=1)
{
	name = n;
	nationality = nat;
	sex = s;
}

void Person::printName()
	{
		cout << name; 
	}

void Person::printNationality() 
	{
		cout << nationality;
	}

.h file for the Person Class

#pragma once
#include <string>
#include <iostream>
using namespace std;

class Person
{
public:
	Person(char* , char* , int);
	
	void printName();
	void printNationality();

private:
	string name, nationality;
	int sex;
};

It works only if I put them in main file. In other words, without separate them. The error in this line

Person creator("Bjarne Stroustrup", "Denmark");

Error: no instance of constructor "Person::Person" matches the argument list.

Any suggestions

[tvrameshmc]

In .cpp file don't write default parameters initialization. Write as below.

Person::Person(char* n, char* nat, int s)
{
	name = n;
	nationality = nat;
	sex = s;
}

In .h file you have to write default parameters initialization as below.

Person(char* n="", char* nat="U.S.A", int s=1);

[CroCo]

@tvrameshmc
thank you so much. It worked.