Reference Variable With Example

Explain Reference Variable in C++ with example

Reference Variable: 

C++ introduces a new kind of variable known as the reference variable. A reference is an alias or an alternative name for an existing variable. All operations applied on reference variables are also applied on original variable.  The address of a reference variable is same as the address of the original variable. Reference variable looks like ordinary variable and behaves like pointer variable. A reference variable can be defined as:
      Datatype  &ref_varible = ori_varible;

     Eg      int a=5;
               int   &b = a;
           cout<<a<<b;  // output will be 5 5.
           b= 20;
               cout<<a<<b;  // output will be  20  20.
Where b is a reference variable of a and a is a referent.
The following points can be noted about reference parameters.
•    A reference can never be null. It must always refer to a valid object  or variable
•    Once a reference variable is created for one variable it cannot be reference variable for another variable.
•    Reference never takes any extra space in memory.
•    Reference has to be initialized while declaring only.
Limitation:  A variable(referent) can have more then one references but one reference variable can have
                 only one referent.