I get the following error message when I try to compile this code with use strict turned on:

sub failsToCompile {
  my $hashRef = shift;
  my $val;
  foreach my $key (keys %$hashRef) {
    $val .= $hashRef{$key};
  }
  return $val;
}

[download]
Error Message: Global symbol "%hashRef" requires explicit package name ...

I finally discovered a work around. When I rework the code a little to be like the following sub then the error message goes away. So, I know how to get around it now, but my question is... why? Why do I have to do that? Why can't I refer to the hash that the hash reference points to in the for loop without dereferencing it first and assigning it to another variable as I did in the following sub? Also, what is making perl think this is a global symbol? Thanks in advance for input/explanations. 

sub worksCompilingFine {
  my $hashRef = shift;
  my %hash = %$hashRef;
  my $val;
  foreach my $key (keys %hash) {
    $val .= $hash{$key};
  }
  return $val;
}

[download]

In reply to Hash dereferencing in a loop by willjones

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