Question

I cannot seem to access the map in the parent class from the child class, as I try to output the contents of the map and nothing is displayed.

BELOW I HAVE ADDED IN THE FULL CODE, OVERALL IF I POPULATE THE MAP IN THE transLateMask() it will then print out the contents, however if i populate the map in the populate() it will print out nothing and I do not know why?

Here is my code.

//HEADER FILE
//////PARENT CLASS
#include <iostream>
#include <string>
struct TTYElementBase 
{
    //some code here
};

class element
{
    public:
    std::map<char,std::string> transMask;
    std::map<char,std::string>::iterator it;
    void populate();
};

//////CHILD CLASS .HPP

class elementV : public element
{
    public :
    std::string s1;
    std::string s2;
    elementV();
    friend ostream &operator<< (ostream &, const elementV &);
    void transLateMask();
};

//CPP FILE #include "example.h"

elementV::elementV()
{
}

void element::populate()
 {
    transMask['D']='D'; //WILL PRINT OUT NOTHING IF I POPULATE HERE 

 }


void elementV::transLateMask()
{

    for ( it=transMask.begin() ; it != transMask.end(); it++ )
        std::cout << (*it).first << std::endl;
}

int main()
{
    element e;
    e.populate();
    elementV v;
    v.transLateMask();
}

It doesn’t output anything – why is that?

Answer 1

The call to e.populate() populates e.transMask, not v.transMask. You need to call v.populate().