Building Hashrefs

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

Hello,
If I want to reference an item in a hashref like this:

$hash_ref->{'sender'}
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How do I build the data structure?

Can I just say,

my $hash_ref;

$hash_ref->{'sender'}='address';
$hash_ref->{'date'}='date';

etc
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I assume this is just refering to an array of hashrefs right?

@{$q_mail}
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Your help greatly appreciated as always.

Tom

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Re: Building Hashrefs by pbeckingham (Parson) on Jul 23, 2004 at 14:37 UTC
For hash refs: `my $hash_ref = {}; # valid hash_ref, empty hash $hash_ref->{'key'} = 'value'; # hash now contains one k-v pair # but hash_ref unchanged` [download] The following code is just dereferencing an array ref. `@{$q_mail}` [download]	[reply] [d/l] [select]
Re: Building Hashrefs by Fletch (Bishop) on Jul 23, 2004 at 14:38 UTC
`perldoc perlreftut`, `perldoc perldsc`, `perldoc perllol`, `perldoc perlref`.	[reply] [d/l] [select]
Re^2: Building Hashrefs by ccn (Vicar) on Jul 23, 2004 at 14:40 UTC
perldoc perlreftut, perldoc perldsc, perldoc perllol, perldoc perlref.	[reply]
Re: Building Hashrefs by deibyz (Hermit) on Jul 23, 2004 at 14:42 UTC
Hi, First, `perldoc perlref` is your friend! Have a look and your life will be much better. In your example, the structure `$scalar->{}` will autovivify () an anonymous HASH reference, just as: `my $hash_ref = {}; ${$hash_ref}{foo} = "bar";` [download] () More about autovivification: http://tlc.perlarchive.com/articles/perl/ug0002.shtml Updated: Fixed typos =/	[reply] [d/l] [select]
Re^2: Building Hashrefs by pbeckingham (Parson) on Jul 23, 2004 at 14:54 UTC
You have omitted the sigil on your declaration, and misspelled the variable while dereferencing it for some reason. `my $hash_ref = {}; $hash_ref->{foo} = "bar";` [download]	[reply] [d/l]
Re^3: Building Hashrefs by deibyz (Hermit) on Jul 23, 2004 at 15:06 UTC
Thanks, Fridays are so bad... Updated.	[reply]