Question - Describe PRIVATE, PROTECTED and PUBLIC – the differences and give examples.
Answer -
class Point2D{
int x; int y;
public int color;
protected bool pinned;
public Point2D() : x(0) , y(0) {} //default (no argument) constructor
};
Point2D MyPoint;
You cannot directly access private data members when they are declared (implicitly) private:
MyPoint.x = 5; // Compiler will issue a compile ERROR
//Nor yoy can see them:
int x_dim = MyPoint.x; // Compiler will issue a compile ERROR
On the other hand, you can assign and read the public data members:
MyPoint.color = 255; // no problem
int col = MyPoint.color; // no problem
With protected data members you can read them but not write them: MyPoint.pinned = true; // Compiler will issue a compile ERROR
bool isPinned = MyPoint.pinned; // no problem