C++ Interview Questions and Answers

 

Define a constructor - What it is and how it might be called (2 methods).

Answer1



constructor is a member function of the class, with the name of the function being
the same as the class name. It also specifies how the object should be initialized.





Ways of calling constructor:



1) Implicitly: automatically by complier when an object is created.



2) Calling the constructors explicitly is possible, but it makes the code unverifiable.





Answer2



class Point2D{



int x; int y;



public Point2D() : x(0) , y(0) {} //default (no argument) constructor



};





main(){





Point2D MyPoint; // Implicit Constructor call. In order to allocate memory on stack,
the default constructor is implicitly called.





Point2D * pPoint = new Point2D(); // Explicit Constructor call. In order to allocate
memory on HEAP we call the default constructor.

Posted by:Richards