Re: looping over an array of hashes
On Fri, 2006-28-04 at 15:40 +0100, Graeme McLaren wrote:
> Hi all, I need to loop over an array of hashes and assign a new hashref if a
> condition is met:
>
> I have a scalar which contains an array of hashes:
>
> $locations = [
> {
> 'location_name' => 'Fionas House',
> 'location_id' => '0027'
> },
> {
> 'location_name' => 'Central Locations',
> 'location_id' => ''
> },
> {
> 'location_name' => 'The Queen\'s Hoose',
> 'location_id' => '1076'
> },
> {
> 'location_name' => 'Santa',
> 'location_id' => '1075'
> },
> ]
>
>
>
> I want to add an new hash ref in if, for example,
>
> if($x ==0027){
> $locations->[0]->{'location_status'} = 'true'
>
> }
>
>
> I've been at this a few hours and I'm not getting anywhere, can anyone
> suggest a way to do this?
An reference to an array can be dereferenced to an array:
for my $item ( @$locations ){ # $item references each hash in the list
if( $item->{location_id} == 0027 ){
$item->{location_status} = 'true';
}
}
--
__END__
Just my 0.0002 million dollars worth,
--- Shawn
"For the things we have to learn before we can do them, we learn by doing them."
Aristotle
* Perl tutorials at http://perlmonks.org/?node=Tutorials
* A searchable perldoc is at http://perldoc.perl.org/
--
To unsubscribe, e-mail: [EMAIL PROTECTED]
For additional commands, e-mail: [EMAIL PROTECTED]
looping over an array of hashes
Hi all, I need to loop over an array of hashes and assign a new hashref if a
condition is met:
I have a scalar which contains an array of hashes:
$locations = [
{
'location_name' => 'Fionas House',
'location_id' => '0027'
},
{
'location_name' => 'Central Locations',
'location_id' => ''
},
{
'location_name' => 'The Queen\'s Hoose',
'location_id' => '1076'
},
{
'location_name' => 'Santa',
'location_id' => '1075'
},
]
I want to add an new hash ref in if, for example,
if($x ==0027){
$locations->[0]->{'location_status'} = 'true'
}
I've been at this a few hours and I'm not getting anywhere, can anyone
suggest a way to do this?
Cheers,
G :)
--
To unsubscribe, e-mail: [EMAIL PROTECTED]
For additional commands, e-mail: [EMAIL PROTECTED]
Re: Looping over an array of hashes problem
Graeme McLaren wrote:
> Morning all, I have a problem that I can't see a way around. Basically
> I have an array of hashes and I want to get the key and value of each
> hash but with the following code I'm getting:
>
> Type of arg 1 to keys must be hash (not array element) at
> /usr/lib/perl5/vendor_perl/Purchaser/Common.pm line 477, near "]) "
>
> #code:
>
> foreach my $key (keys $AoH[$map_loop{$i}]) {
> my $value = $AoH[$map_loop{$i}]->{$key};
>
> }
>
>
> Is there a way to loop over an array of hashes?
foreach my $key ( keys %{ $AoH[ $map_loop{ $i } ] } ) {
my $value = $AoH[ $map_loop{ $i } ]{ $key };
}
John
--
use Perl;
program
fulfillment
--
To unsubscribe, e-mail: [EMAIL PROTECTED]
For additional commands, e-mail: [EMAIL PROTECTED]
Re: Looping over an array of hashes problem
maybe u would try:
foreach my $key (keys %{$AoH[$map_loop{$i}]}) {
...
}
because $AoH[$map_loop{$i}] is just a ref,so u get wrong.
On Thu, 08 Sep 2005 09:42:33 +0100, "Graeme McLaren"
<[EMAIL PROTECTED]> said:
> Morning all, I have a problem that I can't see a way around. Basically I
> have an array of hashes and I want to get the key and value of each hash
> but
> with the following code I'm getting:
>
> Type of arg 1 to keys must be hash (not array element) at
> /usr/lib/perl5/vendor_perl/Purchaser/Common.pm line 477, near "]) "
>
> #code:
>
> foreach my $key (keys $AoH[$map_loop{$i}]) {
> my $value = $AoH[$map_loop{$i}]->{$key};
>
> }
>
>
> Is there a way to loop over an array of hashes?
>
>
> Cheers for any light you can shed on this?
>
>
> Cheers,
>
> Graeme :)
>
>
>
> --
> To unsubscribe, e-mail: [EMAIL PROTECTED]
> For additional commands, e-mail: [EMAIL PROTECTED]
>
>
>
--
Jeff Pan
[EMAIL PROTECTED]
--
http://www.fastmail.fm - mmm... Fastmail...
--
To unsubscribe, e-mail: [EMAIL PROTECTED]
For additional commands, e-mail: [EMAIL PROTECTED]
Looping over an array of hashes problem
Morning all, I have a problem that I can't see a way around. Basically I
have an array of hashes and I want to get the key and value of each hash but
with the following code I'm getting:
Type of arg 1 to keys must be hash (not array element) at
/usr/lib/perl5/vendor_perl/Purchaser/Common.pm line 477, near "]) "
#code:
foreach my $key (keys $AoH[$map_loop{$i}]) {
my $value = $AoH[$map_loop{$i}]->{$key};
}
Is there a way to loop over an array of hashes?
Cheers for any light you can shed on this?
Cheers,
Graeme :)
--
To unsubscribe, e-mail: [EMAIL PROTECTED]
For additional commands, e-mail: [EMAIL PROTECTED]
Re: looping over an array of hashes
On Fri, Jun 01, 2001 at 03:29:43PM -0700, Chuck Ivy wrote:
> First post, quick question:
>
> I've got an array of hashes that I'm defining the most basic way I can...
>
> my $gSeasonID;
> my @season_list = '';
> while (@fields = $sth->fetchrow_array) {
> $gSeasonID = $fields[0];
> $season_list[$gSeasonID]{number} = $fields[1];
> $season_list[$gSeasonID]{title} = $fields[2];
> $season_list[$gSeasonID]{active} = $fields[3];
> }
>
> where @fields is coming from a DBI query.
>
> Essentially I have
>
> $season_list[1]{number} = 1;
> $season_list[1]{title} = 'Season One';
> $season_list[1]{active} = 0;
> $season_list[2]{number} = 1;
> $season_list[2]{title} = 'Season Two';
> $season_list[2]{active} = 1;
>
> That's fine, and it seems to be writing correctly. But I'd like to loop
> on my array index later to get back, say {title} from each season.
>
> Is there a clean way to do this with foreach or while? What I'd be
> looking for would be $season_list[$loop_season]{name}, if I were using a
> for loop with $loop_season as my index. Is there a way to do this
> with $_ or something and foreach so that I don't have to know the size
> of my array?
Each element in @season_list is just a reference to a hash, so you can
loop through it with foreach using code like this:
foreach my $sl (@season_list) {
print "$sl->{title}\n";
}
Re: looping over an array of hashes
On Fri, Jun 01, 2001 at 03:29:43PM -0700, Chuck Ivy wrote:
> First post, quick question:
>
> I've got an array of hashes that I'm defining the most basic way I can...
>
> my $gSeasonID;
> my @season_list = '';
> while (@fields = $sth->fetchrow_array) {
> $gSeasonID = $fields[0];
> $season_list[$gSeasonID]{number} = $fields[1];
> $season_list[$gSeasonID]{title} = $fields[2];
> $season_list[$gSeasonID]{active} = $fields[3];
> }
First things first, you don't really nead $gSeasonID, this will work
just as well:
$season_list[$fields[0]] = $fields[1];
Second of all, I think this problem becomes a lot easier if you use
hashes of hashes, like so:
$season_list{$fields[0]}{number} = $fields[1];
Because now you can loop over the seasons like so:
foreach (keys %season_list) {
print $season_list{$_}{title}; # or do whatever to this data
}
Now you don't need to fuss with array size or index values at all.
Hope this helps!
Bill
--
Bill Stilwell
[EMAIL PROTECTED]
It's all margins.
Oh, just read my weblog: http://www.marginalia.org
Re: looping over an array of hashes
First ugly thought goes like this:
my @season_list = '';
while (my @fields = $sth->fetchrow_array) {
for (my $i = 1; $i < @fields; $i++) {
$season_list[$fields[0]]{('number', 'title', 'active')[$i]} = $fields[$i];
}
Second thought is:
Why not use $sth->fetchrow_hashref? The only reason I can think of
would be a case where your select looked like this
select a.id, b.name, a.name from tab1 a, tab2 b where a.id = b.id;
in this case Informix (and many other databases) returns (id, name,
name) from the $sth->{NAME} call. This can be corrected by writing you
sql like this (please adjust for your flavor of sql):
select a.id, b.name as b_name, a.name as a_name
from tab1 a, tab2 b
where a.id = b.id;
On 01 Jun 2001 15:29:43 -0700, Chuck Ivy wrote:
> First post, quick question:
>
> I've got an array of hashes that I'm defining the most basic way I can...
>
> my $gSeasonID;
> my @season_list = '';
> while (@fields = $sth->fetchrow_array) {
> $gSeasonID = $fields[0];
> $season_list[$gSeasonID]{number} = $fields[1];
> $season_list[$gSeasonID]{title} = $fields[2];
> $season_list[$gSeasonID]{active} = $fields[3];
> }
>
> where @fields is coming from a DBI query.
>
> Essentially I have
>
> $season_list[1]{number} = 1;
> $season_list[1]{title} = 'Season One';
> $season_list[1]{active} = 0;
> $season_list[2]{number} = 1;
> $season_list[2]{title} = 'Season Two';
> $season_list[2]{active} = 1;
>
> That's fine, and it seems to be writing correctly. But I'd like to loop
> on my array index later to get back, say {title} from each season.
>
> Is there a clean way to do this with foreach or while? What I'd be
> looking for would be $season_list[$loop_season]{name}, if I were using a
> for loop with $loop_season as my index. Is there a way to do this
> with $_ or something and foreach so that I don't have to know the size
> of my array?
--
Today is Boomtime, the 6th day of Confusion in the YOLD 3167
Fnord.
looping over an array of hashes
First post, quick question:
I've got an array of hashes that I'm defining the most basic way I can...
my $gSeasonID;
my @season_list = '';
while (@fields = $sth->fetchrow_array) {
$gSeasonID = $fields[0];
$season_list[$gSeasonID]{number} = $fields[1];
$season_list[$gSeasonID]{title} = $fields[2];
$season_list[$gSeasonID]{active} = $fields[3];
}
where @fields is coming from a DBI query.
Essentially I have
$season_list[1]{number} = 1;
$season_list[1]{title} = 'Season One';
$season_list[1]{active} = 0;
$season_list[2]{number} = 1;
$season_list[2]{title} = 'Season Two';
$season_list[2]{active} = 1;
That's fine, and it seems to be writing correctly. But I'd like to loop
on my array index later to get back, say {title} from each season.
Is there a clean way to do this with foreach or while? What I'd be
looking for would be $season_list[$loop_season]{name}, if I were using a
for loop with $loop_season as my index. Is there a way to do this
with $_ or something and foreach so that I don't have to know the size
of my array?
