Question

NOTE: I use pseudocode in my question

lets say i have a class called circle with an interface called
circle.h which
i also have a method called readdata but this is defined in another
class called rectangle(rectangle.h is the interface )
i want to call the method readdata in my circle class and pass in my
private member variable which is a vector. How can this be done? is it
correct to pass in a PRIVATE member variable by reference
to another class. Isn’t this defeating the whole purpose of having
private member variables because now i am giving class rectangle
access to circle class vector variable since i pass it in by reference. Here is how i
do it(psuedocode)

circle.h

private:
vector<struct> vect;

public:
dataread()

circle.cpp

rectangle.h

readdata(vector &)




method dataread() //class method to fill up my struct
{
 rectangle::readdata(vect);   //i call rectangle readdata method but i
 pass in a reference to my memebr variable....is this safe?
}

should i just declare the vector locally(in dataread method) and
assign it to the reference? any help would be greatly appreciated.
Right now it compiles but i have been told this is not good
programming practice

Answer 1

I think I get what you are asking. Yes, you can pass a reference to your private data and No, you shouldn’t do it. You can pass a const reference so that it can’t be modified or pass a new vector with the contents copied. The best thing to figure out is why you need to do it that way, then figure out the best method for getting the data there.