in reply to How would I write this using map?

Hello,

I don't think your code works. In keys $obj->things, keys probably complains about not being given a hash.

Anyhoo, You don't need map here:

$things = [ sort keys %{$obj->things} ];

A common reason you'd want map is if ->things returned a list of objects and you needed to call a method on all of them and collect the output: 

# an array ref of all the things' names
$names = [ map $_->name, $obj->things ];

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hth,

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Re^2: How would I write this using map?
by puudeli (Pilgrim) on Jan 13, 2009 at 11:04 UTC
    The code most likely works. Without knowing the object internals you really can not say what things the object contains and in what data structure. A hash is the most natural way to store data with objects so I would assume that things returns a hash.
    --
    seek $her, $from, $everywhere if exists $true{love};
[reply]
[d/l]
      I can't see how this would work. I tried to create some mock code:
      use strict;

{
    package MyObj;

    sub new {
        my %obj; bless( \%obj, $_[0] ); return( \%obj );
    }

    sub items {
        my @things = ( 'key1' => 'v1', key2' => 'v2', );
        return( @things );
    }
}

my $myobj = MyObj->new();
print( "$_\n" ) foreach ( sort keys( $myobj->items() ) );

      [download]
      but kept getting this error:
      Type of arg 1 to keys must be hash
(not subroutine entry) at /tmp/deleteme.pl
line 25, near ") ) "

      [download]
[reply]
[d/l]
[select]

      You cant return a hash from a function. Only lists and scalars.

[reply]
        Got modded down for being right :-)
[reply]

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