Indomitus has asked for the wisdom of the Perl Monks concerning the following question:

Sorry if this has been asked before but I can't seem to make SuperSearch do anything except give me errors and the google search is somewhat hard to use on this site. I'm trying to pass a hash reference from fetchrow_hashref into a function and it's not working. 
  my $book_hashref = $sel_cursor->fetchrow_hashref;

  display_basic($book_hashref);

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then 
  sub display_basic
  {
    my $book_ref = shift;

    print "$book_ref->{'name'}<br>\n";
  }

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When I run this I get this error: 
"my" variable $book_ref masks earlier declaration in same scope at Dis
+playStuff.pm line 100.
syntax error at DisplayStuff.pm line 96, near "sub display_basic"
syntax error at DisplayStuff.pm line 102, near "}"

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I'm somewhat new to hash references so if somebody could enlighten me as to what I need to do to make this work (or at least point me at a site I missed during my searching) I would greatly appreciate it. Thanks in advance.

Replies are listed 'Best First'.
Re: Passing hash references into subs
by Abstraction (Friar) on Jul 18, 2002 at 03:29 UTC
    You are passing/accessing the hash reference correctly. My guess is there's something else wrong that's causing this error. Post more code and maybe something else will surface.
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Re: Passing hash references into subs
by thelenm (Vicar) on Jul 18, 2002 at 03:33 UTC
    The code that you posted looks fine to me, but from the error messages you're getting, it looks like there is a syntax error near line 96 in DisplayStuff.pm. You should fix the syntax error (possibly a missing or extra curly brace?) before doing anything else.

    -- Mike

    --
    just,my${.02}

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Re: Passing hash references into subs
by graff (Chancellor) on Jul 18, 2002 at 04:49 UTC
    Based on this part of the error diagnostics:

    "my" variable $book_ref masks earlier declaration in same scope at DisplayStuff.pm line 100

    the first thing I'd do is search backward in the module from line 100, looking for "$book_ref", to see if it's declared with "my" at some point outside of any other subroutine -- i.e. lexically "global" within the module file (excuse me if those terms are not exactly correct, but I hope you get the idea).

    The other possibility, given the nature of the syntax error reports, is that a previous sub or other block is lacking a closing curly brace, causing the "sub display_basic" to be considered as part of some other block of code (which also happens to declare its own "my $boof_ref"); if you use a programmer's text editor that supports automatic indentation (like (x)emacs) -- in the sense that the editor can parse the code well enough to indent a line appropriately, based on the current bracketing depth -- this can help a lot to watch for cases where you've forgotten a close-bracket somewhere.

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Re: Passing hash references into subs
by Indomitus (Scribe) on Jul 18, 2002 at 03:40 UTC
    The other thing I forgot to mention is that this is in a module. I don't know if that makes a difference.
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      Possibly. But because the problem doesn't appear to be in the code you posted we'll need to see more code to help.
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Re: Passing hash references into subs
by cfreak (Chaplain) on Jul 18, 2002 at 04:02 UTC

    At least in my experieance the -> operator doesn't interpolate. You can do one of two things:

    print $book_ref->{'name'},"<br>\n";

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    Or: 
    print "$$book_ref{'name'}<br>\n";

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    To me the first method seems cleaner but its just personal preference.

    Hope that helps
    Chris

    UPDATE: I stand totally correctly and apologize for my ignorance. Thanks thelenm :)

    Lobster Aliens Are attacking the world!
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      The original code should work fine. Try this example: 
      my $hashref = {'name' => 'Homer'};
print "$hashref->{'name'}\n";

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      -- Mike

      --
      just,my${.02}

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