Yes it is easy to test.

I want a lojical explanation, not "look up this", "test that". Don't you think it's abysmal when such a fundamental and simple question gets the answer along the lines of "test it"?

The answer is "9".

Sooooo. $rx refers to the _variable_name_ @xxx.

It's not a pointer, not really. It's more like a true C++ reference. In C++, there is a world of difference between

char *a = b;

and

char *&a = b;

On the other hand, when we do $rx = [1,2,3]; it behaves like true pointer.

There is a simple rule in there, just waiting to pop out. I can't quite grasp it. My stream of consciousness follows.

I guess the point would be that in Perl, variables are not names of (pointers to) memory areas, but rather "resizable" and type-safe memory areas themselves. It's like having a virtual machine where the word at a given address can contain arbitrary-size array, or either string or number - no matter. The address (variable name) stays the same.

On the other hand, the "kind" of variable cannot be changed (array, hash, scalar, typeglob(?))

In this context, the difference between [] amd () becomes very interesting... I have a feeling that one of them is a literal, the other an operator. Or something.

OK, I am rambling. But I think that the learned company here is pushing me in the right direction. Thank you.

...it's possible that a particular piece of code may be ambigious - meaning that the compiler writer can choose how to implement it.

So, simply "testing it" isn't always a solution.

However, in this case, the question of what is happening (and why) require first understanding what did happen. (Thus, "test it")

My rambling non-official option:

scalars are probably implemented as pointers (they point to something) with logic to do necessary things, such as convert between integer and characters on the fly
arrays are a structure, with each element being a scalar.
hashes are a structure (same as array), except that key and value are scalars

So...an array and a hash cannot be a member of an array or hash. (Back to that whole reference thing).

@xxx = (1, 2, 3); --- creates an array xxx and give its the values to the list (1,2,3) (lists and arrays are different - lists are a collection of scalars, lacking the structure of an array. ie: can't get a size of a list, iirc)

$rx = [1,2,3]; --- the [] create an anonymous array (ie: this IS an array). and allows the $rx to reference this array.

so @xxx = (1,2,3), $rx = \\@xxx; is very different from @xxx = (1,2,3), $rx = [1,2,3]; (there are 2 arrays created in the 2nd example).

now...to really play with your mind, 2 things....

You can create N number of references to a variable...

$reference4 = \\\\\\\\"hello!";

How to reference this reference to a reference to a reference?
print $$$$$refenence4;
Perl also has Symbolic references -
$variablex = 1;
$symbolic_x = "variablex";

print $$symbolic_x;

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