In C++, a reference variable is an alias for something else, that is, another name for an already existing variable.

So suppose we make Sonny a reference to someone named Songqiao. You can refer to the person as either Sonny or Songqiao.

Let’s take a look at how we can do this with code. Suppose we have an int variable already called songqiao, we can create an alias to it by using the & sign in the declaration:

int &sonny = songqiao;

So here, we made sonny a reference to songqiao.

Now when we make changes to sonny (add 1, subtract 2, etc), songqiao also changes.

Two things to note about references:

1. Anything we do to the reference also happens to the original.
2. Aliases cannot be changed to alias something else.