Comments on: 11.4 — Constructors and initialization of derived classes

By: floatingDivs

floatingDivs — Sun, 13 Mar 2011 07:55:12 +0000

The base class constructor Base(int) will be used to initialize m_nValue to 5, and the derived class constructor will be used to initialize m_dValue to 1.3!

Wouldn’t it be that the base class constructor would be used to initialize m_nValue to 1.3 and derived class constructor would be used to initialize m_dValue to 5 (which wouldn’t work since the base class constructor requires an integer)?

By: Dhaval

Dhaval — Tue, 21 Dec 2010 11:32:17 +0000

Hi I have problem of calling constructor for base class from derived class. For that I have used above example. But called constructor externally.

//a.h
#ifndef A_H_
#define A_H_
#include
class A
{
public:
A(int nValue)
{
std::cout << "A: " << nValue << "\n";
}
};
#endif

//b.h
#ifndef B_H_
#define B_H_
#include
class B: public A
{
public:
B(int nValue, double dValue)
: A(nValue)
{
std::cout << "B: " << dValue << "\n";
}
};
#endif

//c.h
#ifndef C_H_
#define C_H_
#include
class C: public B
{
public:
C(int nValue, double dValue, char chValue);
};
#endif

//c.cpp
#include
#include “a.h”
#include “b.h”
#include “c.h”
C::C(int nValue, double dValue, char chValue):B(nValue, dValue)
{
std::cout << "C: " << chValue << "\n";
}

//main.cpp
#include
#include

#include “a.h”
#include “b.h”
#include “c.h”

using namespace std;

int main()
{
C cClass(5, 4.3, ‘R’);
system(“PAUSE”);
return EXIT_SUCCESS;
}

when I compile this code I get error:
multiple definition of `C::C(int, double, char)’

I dont understand why this error come. Any idea? Please let me know.

By: sorin

sorin — Thu, 09 Sep 2010 22:16:11 +0000

this is a very good tutorial. thanks Alex!

By: MrAlshahawy

MrAlshahawy — Fri, 03 Sep 2010 13:54:39 +0000

Your tutorial is more than great, Many thanks for this effort, it is really appreciated, Keep up the good work.

By: TutLover

TutLover — Thu, 29 Jul 2010 19:37:27 +0000

For Baseball example by default bIsMale Should be bIsMale = true when sending parameters to Person… ;p

BTW Love Your Tutorials…

By: Taiwan boy

Taiwan boy — Wed, 02 Jun 2010 04:45:57 +0000

Thanks alot, this article saves me!

By: baldo

baldo — Sat, 22 Aug 2009 20:18:26 +0000

The advantage is only if the base class constructor changes. But if the base class constructor parameters change, then you need to rewrite all of yours derived class constructors…

By: cammy

cammy — Sat, 09 May 2009 11:50:02 +0000

I have been getting on well with the tutorials and have learnt a lot. I was just wondering if they cover proper OOP because, as yet, there has been none and with only a few more lessons til the end, I am getting worried that it will not be covered. For example, “How do you output physical objects to the screen such as buttons and hyperlinks?

Thanks

Cammy

By: ashish aec

ashish aec — Wed, 19 Nov 2008 08:08:12 +0000

This is the exmple of multiple inheritance.
in which class a is base class and class b and c is drived class .
the base class a is publicly inherit by drive class b and c.
should read with 100% efficency.
thanks.

By: gswrg

gswrg — Wed, 22 Oct 2008 10:28:29 +0000

In this example, class C is derived from class B, which is derived from class C

should read

In this example, class C is derived from class B, which is derived from class A

[ Fixed! Thank you. -Alex ]