Re: How to detect a hash container key from a referenced sub value

Forgive me if I've missed something obvious, but why don't you just create a subroutine that accepts a hash and calculates the sum.

My thoughts too. If you employ Phrase objects, you can even make it so that the total will automatically update as you add a new quantity key, e.g. "qtyCont":

use strict;
use warnings;
use 5.010;

use Phrase;

my $phr1 = Phrase->new();

$phr1->quantities("qty", 1);
say $phr1->total_quant;

$phr1->quantities("qtySum", 5);
say $phr1->total_quant;

$phr1->quantities("qtyCont", 8);
say $phr1->total_quant;

--output:--
1
6
14
[download]

/\/\/\/\/\/\/\

package Phrase;

use strict;
use warnings;
use 5.010;

sub new {
    my $self = {};

    $self->{QUANTITIES} = {};
    $self->{TOTAL_QUANT} = 0;

    bless($self);
    return $self;
}

sub total_quant {
    my $self = shift;
    return $self->{TOTAL_QUANT};
}

sub quantities {
    my $self = shift;
    my $key = shift;

    if (@_) {
        my $quant = shift;

        $self->{QUANTITIES}->{$key} = $quant; 
        $self->{TOTAL_QUANT} += $quant;
    }

    return $self->{QUANTITIES}->{$key};
}

1;
[download]

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Re^2: How to detect a hash container key from a referenced sub value by igoryonya (Pilgrim) on Dec 03, 2009 at 10:56 UTC
So, I get it now, the verdict is that I have to create a module (package) to describe an object. I guess, I should read about objects. I've made attempts to learn it before, but there were few things that stopped me. One that I described in reply to FalseVinylShrub, the inability to use the same script file for describing an object and also, I couldn't understand the purpose of the bless function.	[reply]
Re^3: How to detect a hash container key from a referenced sub value by 7stud (Deacon) on Dec 03, 2009 at 17:38 UTC
I couldn't understand the purpose of the bless function Normally, if you have a hash reference: `my $hash = { a => 1, b => 2 };` [download] you can write: `say $hash->{a};` [download] but you cannot use a hash reference to call a function, e.g. `$hash->some_func()` [download] If you look at the code that creates a class, the new() function creates a variable called $self and assigns it a reference to a hash. bless() makes it so that you can use the hash reference to call functions. An object is different from any other data type in Perl in one and only one way: you may dereference it using not merely string or numeric subscripts with simple arrays and hashes... `$aref->[0]` `$href->{'a'}` ...but with named subroutine calls... `$href->some_func()` In a word, with methods. perltoot	[reply] [d/l] [select]