Question

I understand the reference variable concept. It’s an alias to the other variable.

int varA = 100;
int &varB = varA;  

Here varB is a referring to varA, both pointing to same memory location. Changes to one variable reflect in the other.

Question:

1. a) int &c = 100;
   What is the meaning of the above statement, and how does it differ from the following?
   b) int c = 100;

2. Is there any scenario where we need to use 1(a) rather than 1(b)?

Answer 1

All are correct, except this:

int &c = 100; //error

It will give compilation error both in C++03, and C++11. It is because it attempts to bind non-const reference to a temporary object (created out of 100) which is disallowed.

In C++11, you could do this, however:

int && c = 100; //ok

It is called rvalue-reference.

You could bind const reference to a temporary though (both in C++03, and C++11):

int const & c = 100;

–

int c = 100;

It simply defines an object called c and initializes it with 100. No reference here.