Question

Which constructor definition will produce a compile time error?

(a) className(int x=0);

(b) className(char c);

(c) className(int x=0,char c);

(d) className(char c,int x=0);

I have been asked this question by my college director while I was bunking the class.

Enquiry is from Constructors Overloading in chapter Default Arguments vs Overloading, Upcasting and Downcasting of Object Oriented Programming

Answer 1

Correct answer is (c) className(int x=0,char c);

To explain: The default arguments, just like with member functions, must be listed at last in the argument list. Hence this will produce a compile time error. The compiler doesn’t allow the definition to be executed.