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.

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;
}
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