Question

Which among the following is wrong?

(a) class student{  }; student s;

(b) abstract class student{  }; student s;

(c) abstract class student{  }s[50000000];

(d) abstract class student{  }; class toppers: public student{  }; topper t;

The question was posed to me by my college professor while I was bunking the class.

This intriguing question originated from Objects in portion OOPs Concept & Features of Object Oriented Programming

Answer 1

Correct choice is (b) abstract class student{  }; student s;

For explanation: We can never create instance of an abstract class. Abstract classes doesn’t have constructors and hence when an instance is created there is no facility to initialize its members. Option d is correct because topper class is inheriting the base abstract class student, and hence topper class object can be created easily.