Class has no member named - c++

Question

I am new to c++ and is trying to learn about its Object-Oriented design. I started a small project to test out inheritance and polymorphism but encountered a problem and can't seen to figure out what went wrong.
Whenever I compile, there will be an error "class 'ShapeTwoD' has no member name getx() and gety()". I tried to directly set the x and y value with setx and sety but it still return the same error.
Class ShapeTwoD is the Base class with only the variable 'name' and 'container'. Would appreciate if anyone can direct me to the right direction.
Main.cpp
#include <iostream>
#include <string>
#include "ShapeTwoD.h"
#include "Square.h"
using namespace std;
int main()
{
cout<<endl;
ShapeTwoD *shape2D[100];
ShapeTwoD *sq1 = new Square("Square", true, 4, 6);
cout << sq1->getName() <<endl;
cout << sq1->getContainer() <<endl;
//sq1->setx(4) <<endl;
//sq1->sety(6) <<endl;
cout << sq1->getx() <<endl;
cout << sq1->gety() <<endl;
cout<<endl;
delete sq1;
}
Square.h
#include <iostream>
#include <string>
#include "ShapeTwoD.h"
using namespace std;
class ShapeTwoD; //forward declare
class Square : public ShapeTwoD
{
public:
int x;
int y;
//constructor
Square(string name, bool container,int x, int y);
int getx();
int gety();
void setx(int x);
void sety(int y);
};
Square.cpp
#include <iostream>
#include <string>
#include "Square.h"
#include "ShapeTwoD.h"
Square::Square(string name, bool containsWarpSpace, int coordx, int coordy)
:ShapeTwoD(name, containsWarpSpace)
{
(*this).x = coordx;
(*this).y = coordy;
}
int Square::getx()
{
return (*this).x;
}
int Square::gety()
{
return (*this).y;
}
void Square::setx(int value)
{
(*this).x = value;
}
void Square::sety(int value)
{
(*this).y = value;
}

Answer 1

That's normal... If you declare sq1 as ShapeTwoD, you have access to ShapeTwoD public member methods/attributes. Even it was instanciated with the Square constructor. Cast it as Square, and you can use getx gety. Or declare getx/gety as methods of ShapeTwoD.

Answer 2

Well this is what you should expect since it has shape2D type , Although constructing it with the square constructor won't allow you to access the derived class members but it will allow you to have a safe type cast to use it.. the simplest way to do it is by :
cout << static_cast<Square*>(sq1)->getx() << endl;
cout << static_cast<Square*>(sq1)->gety() << endl;