I've read that once a reference is initialized to an object, it cannot be changed. The following code works, so perhaps I am misunderstanding the concept? (Or do they mean this more in an immutable sense?)
int main()
{
int x = 4;
int& j = x;
cout << j << endl;
int y = 5;
j = y;
cout << j << endl;
}
The following code works, so perhaps I am misunderstanding the concept?
Indeed I'm afraid you are misunderstanding the concept. The expression:
j = y;
Does not re-bind j so that it becomes a reference to y: rather, it assigns the value of y to the object referenced by j. Try this after the assignment:
cout << (&j == &x)
And you will see that 1 is printed (meaning j is still an alias for x).
After initialization, a reference becomes an alias for the object it is bound to. Everything you do on the reference, you do it on the object being referenced.
A reference cannot be re-bound or unbound, and it practically becomes just an alternative name for the object it is bound to.
You're just assigning to the reference, not binding it to a new "object" (technically, not an object). If you print out x, you'll see that it too has changed (omg) :)
What was being conveyed is that a reference cannot be rebound. The assignment is affecting x, not j. The variable j on the other hand is still bound to x even after the assignment.
The reference can't be made to point to a different object at a different Address, but as here, the value of the object itself can be changed.
