Assume the existence of a Window class with a function getWidth that returns the width of the window. Define a derived class WindowWithBorder that contains a single additional integer instance variable named borderWidth, and has a constructor that accepts an integer parameter which is used to initialize the instance variable. There is also a function getUseableWidth, that returns the width of the window minus the width of the border

LANGUAGE: C++

CHALLENGE:

Assume the existence of a Window class with a function getWidth that returns the width of the window. Define a derived class WindowWithBorder that contains a single additional integer instance variable named borderWidth, and has a constructor that accepts an integer parameter which is used to initialize the instance variable. There is also a function getUseableWidth, that returns the width of the window minus the width of the border

SOLUTION:

class WindowWithBorder :public Window{
  public:
    WindowWithBorder(int);
    int getUseableWidth();

  private:
    int borderWidth;
    int windowWidth;
};

WindowWithBorder::WindowWithBorder(int y){
    windowWidth = getWidth();
    borderWidth = y;
}

int WindowWithBorder::getUseableWidth(){
   return windowWidth - borderWidth;
}