Hi coldmiser!

I agree with you, references can be tricky beasties to get the hang of.

You successfully passed refs to your sub and de-referenced them. That's half the battle won already!

But you can, in fact, pass an array or a hash to a sub. Change your test script to test it.

The problem arises when, say, you want to pass two arrays. 

pass_arrays(@array_one, @array_two);

sub pass_arrays{
  my @a1 = @_;
  my @a2 = @_;
}

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Perl will 'flatten' both arrays into one array and copy it into @a1. @a2 will be empty. If you pass refs: 
pass_arrays(\@array_one, \@array_two);

sub pass_arrays{
  my ($a1ref, $a2ref) = @_;
}

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$a1ref and $a2ref now contain the refs you passed and you can use them as you did in your snippet.

You might also write a script that changes the array/hash passed into a sub and then look at what they look like after the sub has been called.

Your snippet also raises the question of scoping (as duff mentions). Have a look at Coping with Scoping to get more of an idea of what going on.

You're nearly there, good luck!

In reply to Re: Small troubles with references by wfsp
in thread Small troubles with references by coldmiser

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