Beefy Boxes and Bandwidth Generously Provided by pair Networks
more useful options
 
PerlMonks  

comment on

( #3333=superdoc: print w/replies, xml ) Need Help??
You should . .
use strict;
$ref in foo() is out of scope becaue it is my'ed in bar(). When bar() returns $ref is garbage collected.

OK folks, here his code with my comments added:

sub foo { ... ########## Note that $ref does not exist(it's undef) ####### my %locations = &bar($dbh); ## Note that $ref did not get passed back from bar ## ... ########## $ref->{'location'} is undef, but 'use strict;' ########## here would have said: "can't use undef as hash" my $location_text = $locations{$ref->{'location'}}; } sub bar { my $dbh = shift; my $sql_loc = qq|SELECT * FROM ndmw_location|; my $sth = $dbh->prepare($sql_loc); $sth->execute or die("..."); my %locations; ########## Note that $ref IS my'ed here ########### while (my $ref = $sth->fetchrow_hashref()) { my $id = $ref->{'id'}; my $location = $ref->{'location'}; $locations{$id} = $location; } $sth->finish; return %locations; ########## Note that $ref goes away here ########### }
And finally,

If I throw all the code into one sub and not try and split it into sub-subs, it all works as expected.

Yes, it does work for him. That's beacuse $ref does not go out of scope.

Updated To make the problem/solution more clear.


In reply to Re: Passing a hash between subs by Cabrion
in thread Passing a hash between subs by wil

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post; it's "PerlMonks-approved HTML":



  • Are you posting in the right place? Check out Where do I post X? to know for sure.
  • Posts may use any of the Perl Monks Approved HTML tags. Currently these include the following:
    <code> <a> <b> <big> <blockquote> <br /> <dd> <dl> <dt> <em> <font> <h1> <h2> <h3> <h4> <h5> <h6> <hr /> <i> <li> <nbsp> <ol> <p> <small> <strike> <strong> <sub> <sup> <table> <td> <th> <tr> <tt> <u> <ul>
  • Snippets of code should be wrapped in <code> tags not <pre> tags. In fact, <pre> tags should generally be avoided. If they must be used, extreme care should be taken to ensure that their contents do not have long lines (<70 chars), in order to prevent horizontal scrolling (and possible editor intervention).
  • Want more info? How to link or How to display code and escape characters are good places to start.
Log In?
Username:
Password:

What's my password?
Create A New User
Chatterbox?
and the web crawler heard nothing...

How do I use this? | Other CB clients
Other Users?
Others contemplating the Monastery: (3)
As of 2021-05-11 15:59 GMT
Sections?
Information?
Find Nodes?
Leftovers?
    Voting Booth?
    Perl 7 will be out ...





    Results (119 votes). Check out past polls.

    Notices?