C++ Interview Questions and Answers

 

Describe PRIVATE, PROTECTED and PUBLIC – the differences and give examples.

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

Posted by:Richards