Question

I have the following sub-routine.

 sub Function{
   my $ref = \($_[0]);
   if(ref($ref) eq 'SCALAR'){
   . . .
   }
}

I am trying to get it to work such that passing a list, scalar or hash to it, it converts that into a reference and depending upon whether that reference is of type ARRAY, SCALAR or HASH, different actions are performed.

It could be called as

Function(%a)
Function($a)
Function(@a)

How can I make $ref be a reference to whatever is passed to the Function? My current approach isn’t working.

Answer 1

You can use a prototyped function. Although Perl 5 prototypes are a total mess, they can be used quite well in this case. As I understand them the prototype

sub Function (\[$@%]) {...}

should solve your problem, and the reference be in $_[0].

The big disadvantage is that the variable you pass has to start with the $, @, or % character, so you can’t call Function with a constant argument directly:

 Function(1)

fails, but

 my $temp = 1;
 Function($temp)

works.

---

Your approach failes, because @_ is a list, and all elements are scalars.