http://www.perlmonks.org?node_id=1015178


in reply to Cant use string(_) as array ref..!!

Update: changed 'indirect' to 'symbolic' as that is what I meant, but blanked out on while I was composing my post.

First off, Kudos for using the strict and warnings pragmas. They will really help you catch typos and silly errors in your script.

push(@{${$key}[0]},1,33); push(@{${$key}[0]},22,11); push(@{${$key}[1]},2,5); push(@{${$key}[2]},3,4);

Ok you are trying to use indirect symbolic referencing to autovivify your hashes and that is not allowed under the strict pragma. You would probably be better off just predeclaring a single hash and use the day names as keys. Did you really want a 4 element array at index 0 and 2 element arrays elsewhere? Tk::Chart::Lines is going to complain about that. Anyway see if this clears anything up for you.

#!/usr/bin/perl use strict; use warnings; use Data::Dumper; use Tk; use Tk::Chart::Lines; my $mw = MainWindow->new( -title => 'Tk::Chart::Lines example', -background => 'white', ); my $chart = $mw->Lines( -title => 'My graph title', -xlabel => 'X Label', -ylabel => 'Y Label', )->pack(qw / -fill both -expand 1 /); my @a = qw/Mon Tue Wed Thurs/; my %days; foreach my $key (@a) { push @{$days{$key}}, [1, 33]; push @{$days{$key}}, [22, 11]; push @{$days{$key}}, [2, 5]; push @{$days{$key}}, [3, 4]; } my $c ='Mon'; # Add a legend to the graph my @legends = ( 'legend 1', 'legend 2', 'legend 3' ); $chart->set_legend( -title => 'Title legend', -data => \@legends, -titlecolors => 'blue', ); # Add help identification $chart->set_balloon(); #print Dumper \$days{$c}; # Create the graph $chart->plot( $days{$c} ); MainLoop;