Technology

The way it works is that there's a symbol table entry for "foo" which has a slot for a hash, scalar, array, glob, etc.

That leads to some super weird behaviour like, for example, if I declare a scalar, hash and array as "x":

$x = "sy";
%x = (foo => "mb");
@x = ("ol", "s!");

You can access them all independently as you're aware:

say "x: ", $x, $x{foo}, @x; # Outputs:  x: symbols!

But what's really going to bake your noodle is I can assign the "x" symbol to something else like this:

*z = *x;

..and then the same thing works with z:

say "z: ", $z, $z{foo}, @z; # Outputs:  z: symbols!

Oneliner if you want to try it:

perl -E '$x = "sy"; %x = (foo => "mb"); @x = ("ol", "s!"); say "x: ", $x, $x{foo}, @x; *z = *x; say "z: ", $z, $z{foo}, @z;'

Congratulations! You now know more about one of Perl's really weird internals than I'd wager most Perl programmers (I have literally never used any of the above for anything actually productive!)