Thread: The '& operator'...

What is the '& operator' and how does it work?

It can mean more than thing. However, I am assuming you are talking about the address of operator. When you have a variable, placing the ampersand (&) before the variable means you want the address of the variable instead of the actual value. For example:

Code:

#include <iostream.h>

int main()
{  int number=4;
    cout<<number;//will display 4
    cout<<&number;//will display some weird #, the address of number
    
    return 0;
}

actually the ampersand is after the variable:

example:
[code]
T& operator [] ...

Yeah, in the example im working with, the ampersand is used in fron of the variable:

Code:

T& operator []

It means a reference to the variable after it. Think of a reference like a pointer. However, the address it refers to cannot be reassigned. Also, there is no need to dereference it when using it. Basically, think of it as an alias. For example, a reference to William Clinton might be Bill Clinton. When refering to one, it modifies both.

Code:

#include <iostream.h>

int main()
{ int number=4;
   int &numreference=number;
   cout<<number;//outputs 4
   cout<<numreference;//outputs 4
   number=7;
   cout<<number;//outputs 7
   cout<<numreference;//outputs 7
   
   return 0;
}

BTW, your example means the function returns a reference to a T type.

unary operator gives you the address as previously stated, useful for passing to functions and pointers, see examples above.

as a binary operator it provides an alternative identity for a memory address, eg

Code:

int number = 4;
int& sameNumber = number;    //& can be beside data type or identifier

cout << number << endl;    //prints 4
cout << sameNumber << endl;    //prints 4