But I wasn't assigning it to a key, only to the value stored at that key's
index.
For example.
If I have %colors
I would like to have
@colors{darks}
@colors{lights}
@colors{greys}
Where those are simply arrays, as I tried to symbolize by the at sign,
which
contain a list of colors of the given description.
Instead, I'm lead to believe that I would have to do.
@{$colors{"darks"}}
Which is fine, but I'm just saying I think the previous syntax looks
nicer.
Take care,
Sina
-----Original Message-----
From: programmingblind-bounce@xxxxxxxxxxxxx
[mailto:programmingblind-bounce@xxxxxxxxxxxxx] On Behalf Of
james.homme@xxxxxxxxxxxx
Sent: Tuesday, October 14, 2008 9:29 AM
To: programmingblind@xxxxxxxxxxxxx
Subject: RE: Perl arrays and hashes
Hi,
Perhaps I didn't read correctly, but I thought he said that you couldn't
assign an array to a key of a hash, but you can assign an array to a value
of a hash. I think this is like a Python or VbScript or JavaScript
dictionary.
Thanks.
Jim
James D Homme, Usability Engineering, Highmark Inc.,
james.homme@xxxxxxxxxxxx, 412-544-1810
"The difference between those who get what they wish for and those who
don't is action. Therefore, every action you take is a complete
success,regardless of the results." -- Jerrold Mundis
Highmark internal only: For usability and accessibility:
http://highwire.highmark.com/sites/iwov/hwt093/
"Sina Bahram"
<sbahram@xxxxxxxx
m> To
Sent by: programmingblind@xxxxxxxxxxxxx
programmingblind- cc
bounce@freelists.
org Subject
RE: Perl arrays and hashes
10/14/2008 08:50
AM
Please respond to
programmingblind@
freelists.org
Thanks much. Is there a reason why you can not assign an array, rather
than
an array reference, to an element of a hash?
Take care,
Sina
-----Original Message-----
From: programmingblind-bounce@xxxxxxxxxxxxx
[mailto:programmingblind-bounce@xxxxxxxxxxxxx] On Behalf Of Octavian
Rasnita
Sent: Tuesday, October 14, 2008 7:13 AM
To: programmingblind@xxxxxxxxxxxxx
Subject: Re: Perl arrays and hashes
This is because for any hash key you can have an array reference as a
value.
You can't have an array as a value for a hash key.
For example, you can't use something like:
%hash = (
key => (1, 2, 3),
);
but you need to use:
%hash = (
key => [1, 2, 3],
);
And when you use $hash{key} you will have the value of this key as a
result.
And that value is an array ref, not an array.
If you want to have the array for that ref, you need to dereference it,
putting the "@" sign before it like:
my $arrayref = [1, 2, 3];
my @array = @$arrayref;
So you need to use @$arrayref and not only @arrayref because there is no
an
array with this name.
$arrayref is a scalar not an array. That scalar is a reference to an
array.
Octavian
----- Original Message -----
From: "Sina Bahram" <sbahram@xxxxxxxxx>
To: <programmingblind@xxxxxxxxxxxxx>
Sent: Tuesday, October 14, 2008 9:00 AM
Subject: RE: Perl arrays and hashes
I did understand all of that, but I suppose I was asking about why perl
was
treating it as a reference rather than doing the conversion itself.
Regardless though, it all works and thanks.
Take care,
Sina
-----Original Message-----
From: programmingblind-bounce@xxxxxxxxxxxxx
[mailto:programmingblind-bounce@xxxxxxxxxxxxx] On Behalf Of Octavian
Rasnita
Sent: Tuesday, October 14, 2008 1:35 AM
To: programmingblind@xxxxxxxxxxxxx
Subject: Re: Perl arrays and hashes
Hi,
You need to write
@{$macs{$key}}
and not
@macs{$key}
because %macs is a hash and not an array to be noted with @ at the
beginning.
The %macs hash has a key named $key which happends to have an array as a
value.
So you first need to specify that you want to address the key $key of
this
hash, using
$macs{$key}
and derefference it to get its value... the array, using @{$macs{$key}}
It is just like when you use
my $hash_key = $macs{$key};
my @array = @$macs_key;
Of course, you need to add more braces like when you use
my @array = @{$hash_key};
because $macs{$key} already contains braces and you need to specify that
the
entire $macs{$key} is an array reference, not only $hash.
Octavian
----- Original Message -----
From: "Sina Bahram" <sbahram@xxxxxxxxx>
To: <programmingblind@xxxxxxxxxxxxx>
Sent: Monday, October 13, 2008 11:38 PM
Subject: RE: Perl arrays and hashes
I'm off to try this out, but can you please explain why that is?
I do understand why you're doing what you're doing, but I'm unclear as
to
why perl isn't doing this automatically?
Take care,
Sina
-----Original Message-----
From: programmingblind-bounce@xxxxxxxxxxxxx
[mailto:programmingblind-bounce@xxxxxxxxxxxxx] On Behalf Of Octavian
Rasnita
Sent: Monday, October 13, 2008 4:24 PM
To: programmingblind@xxxxxxxxxxxxx
Subject: Re: Perl arrays and hashes
Hi,
You need to use:
for my $key (sort(keys(%macs)))
{
print "$key\n";
for my $val (@{$macs{$key}})
{
print "$val\n";
}
print "\n";
}
Octavian
----- Original Message -----
From: "Sina Bahram" <sbahram@xxxxxxxxx>
To: <programmingblind@xxxxxxxxxxxxx>
Sent: Monday, October 13, 2008 10:50 PM
Subject: Perl arrays and hashes
Hi all,
I have a very simple program that loops through a file, whose structure
is
like this.
Key name:
Value1
Value2
Value3
...
Key name:
Value1
Value2
.....
Key name:
Value1
Value2
Value3
Value4
...
And so on
Not hard, right?
I use the following snippet of code to parse that file.
***
open(MACS, "macs.txt");
my @macsFromFile = <MACS>;
chomp @macsFromFile;
my %macs;
my $i = 0;
for my $mac (@macsFromFile)
{
if($mac =~ /10.110.0.*/)
{
$key = $mac;
$i = 0;
@macs{$key} = ();
}
$macs{$key}[$i++] = $mac if($mac =~ /05:.*/);
}
***
Anyways, as far as I can tell, that works fine. When I print out the
keys
of
that hash, I get all the ip addresses I was looking for, but heaven
forbid
I
try to get the values. That's an insane nightmare.
How can I loop through that hash, with each key, looping through each
of
the
arrays stored at each key's index. After all, each key is an IP
address,
and
each IP address has a series of mac addresses associated with it in
this
file, in the form of them being in an array assigned to that key in the
hash.
So I wanted to make sure I parsed the file write. Thus, why not just
print
it out again and compare against the original. I tried the following.
***
for my $key (sort(keys(%macs)))
{
print "$key\n";
for my $val (@macs{$key})
{
print "$val\n";
}
print "\n";
}
***
It prints out a single memory address rather than the list of the
contents
of that array.
Why does it do this?
I am using a for each construct to itterate through an array, and I use
the
@ to indicate that I want array context to be used when I parse
@macs{$key}
... What the heck else should I do to make perl understand I want to
loop
through the array stored at @macs{$key}?
Maybe I'm not doing this right up top? That's what I think the problem
is.
Somehow I've given my hash a reference to an array, rather than the
array
itself.
Help!
Take care,
Sina
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