how to print to screen a vector? - class

Question

I'm implementing the show Deal Or No Deal, there's a class 'box' which in the main file i used to store the random values of the boxes and than, i saved each box in the vector. im trying now to print in the screen the boxes saved in the vector whit the iterator,without succeeding, any help???
//random assignation of pound value to the 22 boxes
for (int e = 1; e < 23; e++)
{
int pos;
bool op = true;
while (op)
{
pos = rand();
if (pos > 0 && pos < 23)
{
if (myArray[pos][1] == 0)
{
myArray[pos][1] = 1;
op = false;
}
}
}
box b(e, myArray[pos][0]); //creating the class box
game_box.push_back(b); //function of the vector to insert a data in it
}
//show boxes
for (auto a = game_box.begin(); a!= game_box.end(); a++)
{
cout << *a << endl;
}

Answer 1

You first need to remove the dereference operator (*) from the a.
Next you need to add an output operator for box. Assuming that box is a class with member data member1 and member2 this would look something like:
friend std::ostream& operator<< (std::ostream &out, const box& b)
{
out << box.memeber1 << " " << box.member2;
}
The key point is that you need to define this operator for every class.
Once you've done that and got it working you might also like to look at this library which defines << operators for all stl containers. This lets you replace
for (auto a = game_box.begin(); a!= game_box.end(); a++)
{
cout << *a << endl;
}
by simply
cout << game_box << endl;

Answer 2

this works..
class Box
{
float pound_contained;
int box_number;
public:
Box(int box_number, float pound_contained);
int getbox_number();
float getpound_contained();
};
int Box::getbox_number()
{
return this->box_number;
}
float Box::getpound_contained()
{
return this->pound_contained;
}
main()
{
vector<Box> game_box;
Box* boxes = &game_box[i];
cout <<boxes->getbox_number()<<endl;
}