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class in a class

Posted on 2000-03-09
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Last Modified: 2010-04-02
Sir, I have created a program in which I created a class called bowler. now I created a new class called node and included an object of bowler class in it as a member. How can I access the member variable of class bowler through node class in main? is their any solution?
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Question by:jamanat
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7 Comments
 
LVL 31

Expert Comment

by:Zoppo
ID: 2600151
Hi jamanat,

there are multiple possibilities, i.e.:

class bowler {
public:
 int m_iNumber;
 int& GetNumber(){ return m_iNumber; } // returns a reference
....
}

class node {
public:
 bowler m_cBowler;
 int& GetBowlerNumber(){ return m_cBowler.GetNumber(); } // returns a reference
....
}

foo ( node& obj )
{
 int number = obj.m_cBowler.m_iNumber; // direct access
 obj.GetBowlerNumber() = 5; // access via wrapper function, mostly the better way
 obj.m_cBowler.GetNumber() = 5; // the same as befor
// for pointers
 node* pNode = &obj;
 number = pNode->m_cBowler.m_iNumber; // direct access
 pNode->GetBowlerNumber() = 5;
 ...
}

hope that helps,

ZOPPO
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LVL 22

Accepted Solution

by:
nietod earned 30 total points
ID: 2600153
It woudl be a very good idea to post your code with a question like this.  But you probalby have something like

class bowler
{
   public:
     int i;
};

class node
{
    public:
        bowler b;
}

Then in main you can have

int main()
{
   node n;

    // set the int called i inside the bowler inside the node to 5.      
    n.b.i = 5;

    rethrn 0;
};
0
 
LVL 22

Expert Comment

by:nietod
ID: 2600165
Now if the data member ("i" in this case) is not public, then you might need to provide "data member access" functions to let you set the data member.  Like

class bowler
{
   int i;
public:
   void set_i(int x) { i = x; };
};

class node
{
   bowler b;
public:
   Set_b_i(int x) { b.set_i(x); };
}

int main()
{
   node n;

   // set the int called i inside the bowler inside the node to 5.  
   n.set_b_i(5);
    return 0
}


Let me know if you have any questions.
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LVL 22

Expert Comment

by:nietod
ID: 2608180
Hello, Zoppo, how did you get it there before me?
0
 
LVL 31

Expert Comment

by:Zoppo
ID: 2611295
Hmmm, do not know ... directly before I posted my comment I reloaded this question and there wasn't anything posted yet...
0
 
LVL 22

Expert Comment

by:nietod
ID: 2611854
I was two minutes later, but I didn't see you there until later.  Or I would have withdrawn my answer.   You probably shoudl have answered, it certainly seems like that qualifies as an answer.
0
 
LVL 31

Expert Comment

by:Zoppo
ID: 2611976
Seems there're sometimes problems with EE's comment database (I know it coz once they lost one of my comments, Q.10288780) ... but who cares   :)

>You probably should have answered...
I'll try to get used to ...

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