A reference variable is an alias, that is, another name for an already existing variable. Once a reference is initialized with a variable, either the variable name or the reference name may be used to refer to the variable.
Creating References in C++:
Think of a variable name as a label attached to the variable's location in memory. You can then think of a reference as a second label attached to that memory location. Therefore, you can access the contents of the variable through either the original variable name or the reference. For example, suppose we have the following example:
int i = 17;
We can declare reference variables for i as follows.
int& r = i;
Read the & in these declarations as reference. Thus, read the first declaration as "r is an integer reference initialized to i" and read the second declaration as "s is a double reference initialized to d.". Following example makes use of references on int and double:
**#include
using namespace std;
int main ()
{
// declare simple variables
int i;
double d;
// declare reference variables
int& r = i;
double& s = d;
i = 5;
cout << "Value of i : " << i << endl;
cout << "Value of i reference : " << r << endl;
d = 11.7;
cout << "Value of d : " << d << endl;
cout << "Value of d reference : " << s << endl;
return 0;
}**
When the above code is compiled together and executed, it produces the following result:
Value of i : 5
Value of i reference : 5
Value of d : 11.7
Value of d reference : 11.7
References are usually used for function argument lists and function return values.
So following are two important subjects related to C++ references which should be clear to a C++ programmer:
1.References as parameters
C++ supports passing references as function parameter more safely than parameters.
2.Reference as return value
you can return reference from a C++ function like a any other data type can be returned.
