inheritance

phuc_tran · December 16th, 2008, 06:52 AM

I'm a newcomer to programming , help me !!!

If I declare :

class B : class A
{
.............
};
What kind of inheritance of B from A ? public , protected , private .
I just guess that's private ??? Help me!!! Thanks a lot .

jabney · December 16th, 2008, 06:01 PM

I just tried some tests and the default class inheritance is private. Here's the compiler message:

1>c:\users\james\documents\visual studio 2008\projects\beginning visual c++ 2008\inh_test\inh_test\inh.cpp(24) : error C2247: 'A::i' not accessible because 'B' uses 'private' to inherit from 'A'

This was using the following class declarations:

Code:

class A
{
public:
    A():i(10){}
    int i;
};

class B : A
{
public:
    B():j(i){}
    int j;
};

The compiler error doesn't occur until the program tries to access class A's variable i.

Code:

B b;
b.i = 5;

phuc_tran · December 16th, 2008, 08:14 PM

Thanhks a lot , jabney. I understand .