Question

Say I have this:

my %hash;

$hash{"a"} = "abc";
$hash{"b"} = [1, 2, 3];

How can I, later on, find out if what was stored was a scalar, like in "abc", or an array, like in [1, 2, 3]?

Answer 1

First of all, your example of an array reference is wrong – your $hash{"b"} will end up with a scalar value: the last element of the list you provided (‘c’ in this case).

That said, if you actually do want to see if you have a scalar or a reference, use the ref function:

my %hash;

$hash{"a"} = "abc";
$hash{"b"} = [qw/a b c/];

if (ref $hash{"b"} eq 'ARRAY') {
  print "it's an array reference!";
}

Docs

• Documentation for the ref function: http://perldoc.perl.org/functions/ref.html