in reply to pushing into arrays of arrays
in thread pushing into arrays of arrays

1t Note: $#array is not the length, but the biggest index.

2nd note:use strict 

#!/usr/bin/env perl
use strict;

my $ar1 = [1,2,3];
my $ar2 = [4,5,6,7];

my @arrays = ($ar1,$ar2);

foreach my $ary (@arrays) {
    print $#{ary}, "\n";
}
__END__
Global symbol "@ary" requires explicit package name at test.pl line 10
+.
Execution of test.pl aborted due to compilation errors.

[download]

3d note: Read perldata and perlref! Really, that helps a lot!

4th note: 

#!/usr/bin/env perl
use strict;
use warnings;

my $ar1 = [1,2,3];
my $ar2 = [4,5,6,7];

my @arrays = ($ar1,$ar2);

foreach my $ary (@arrays) {
    # correct syntax
    print $#{@$ary}, "\n";
    # correct length
    print scalar(@$ary), "\n";
}

[download]

regards,
tomte

Hlade's Law:

If you have a difficult task, give it to a lazy person --
they will find an easier way to do it.

Replies are listed 'Best First'.
Re: Re: pushing into arrays of arrays
by Anonymous Monk on Mar 05, 2004 at 15:08 UTC
    Thanks for that, it helped a lot; but I'm in a bit of a confused pickle.

    I'm using GD::Graph to draw some graphs. GD::Graph expects the data in the form;
    @graphdata=([@array_of_xlabels],[@dataset],[@dataset],other datasets..
+...)

    [download]

    Now, I am trying to do this;
    
@labels=(array,of,labels)

loop
    loop
        build @dataset
    end loop
    push(@sets,[@dataset])
end loop

foreach $se (@sets)
    @set=$#{$se}
    ((some processing))
    push(@fixed,[@set])
end foreach

push(@graphdata,[@labels])

foreach $fi (@fixed)
    @fixd=$#{$fi}
    push(@graphdata,[@fixd])
end foreach

    [download]

    with the aim of ending up with @graphdata looking exactly the same as if I had done;
    @graphdata=([@labels],[@dataset],[@dataset2])

    [download]

    so, pointers and references and whatnots all over the shop, and I'm getting confused.....
[reply]
[d/l]
[select]

      If I'm not mistaken (I didn't run any code), you are pushing lists with one element (namely the bigest index of the list you IMO intend to push) onto @fixed.

      After that you push a lot of arrays containing only 1 (that is: (1,)) onto @graphdata.

      please use strict!

      try something like this, take the time to notice the differences between your example and this one: 

      use strict;

my @labels = qw(my one word labels);

my @graphdata = (\@labels);

my @sets = ();

# looping and data building, fillings @sets

foreach my $set (@sets) {
     my $se = [];
     # process $set into $se
     push @graphdata, $se;
}

my $graph; 
# GD::Graph stuff
my $gd = $graph->plot(\@graphdata);

      [download]

      Try to understand what you are doing, read a lot, debug your code (e.g. use Data::Dumper), read perldata and perlref thoroughly ;-)

      regards,
      tomte

      Hlade's Law:

      If you have a difficult task, give it to a lazy person --
      they will find an easier way to do it.

[reply]
[d/l]

In Section Seekers of Perl Wisdom