Re: Re: Where is my foreach data going to?

It has everything to do with data types! @athelete[$i,$j], $athelete[$i, $j] and $athelete[$i][$j] are completely different. Try to use the Data::Dumper to investigate why:

use strict;
use Data::Dumper;

my @array;

for (my $i=0;$i<2;$i++)
{
  for (my $j=0;$j<2;$j++)
  {
     @array[$i, $j] = "$i.$j";
  }
}
print "Case 1...\n";
print Dumper(@array);

for (my $i=0;$i<2;$i++)
{
  for (my $j=0;$j<2;$j++)
  {
     $array[$i][$j] = "$i . $j";
  }
}
print "Case 2...\n";
print Dumper(@array);

for (my $i=0;$i<2;$i++)
{
  for (my $j=0;$j<2;$j++)
  {
     $array[$i, $j] = "$i . $j";
  }
}
print "Case 3...\n";
print Dumper(@array);
[download]

You will get -

Case 1...
$VAR1 = undef;
$VAR2 = undef;
Case 2...
$VAR1 = [
          '0 . 0',
          '0 . 1'
        ];
$VAR2 = [
          '1 . 0',
          '1 . 1'
        ];
Case 3...
$VAR1 = '1 . 0';
$VAR2 = '1 . 1';
[download]

As you can see, only case 2 gives you what you want, a two dimensional array.

Comment on Re: Re: Where is my foreach data going to? Select or Download Code

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Re: Re: Re: Where is my foreach data going to? by leriksen (Curate) on Sep 18, 2003 at 06:37 UTC
Just one point , when using Data::Dumper::Dumper() to dump an array or a hash, it is often better to pass a reference to the hash/array, as the output looks more like the original data structure - and you avoid the copying overhead of call-by-value vs call-by-refernce `use Data::Dumper; my @array = (1,2,3,4,5,6,7); print Dumper(\@array); my %hash; # below is a hash slice - you should learn about these @hash{@array} = @array;# a hash whose keys == its values print Dumper(\%hash);` [download] results in the output `$VAR1 = [ 1, 2, 3, 4, 5, 6, 7 ]; $VAR1 = { '7' => 7, '1' => 1, '2' => 2, '3' => 3, '4' => 4, '5' => 5, '6' => 6 };` [download] which to my eyes seems nicer	[reply] [d/l] [select]
Re: Re: Re: Re: Where is my foreach data going to? by demerphq (Chancellor) on Sep 18, 2003 at 11:34 UTC
which to my eyes seems nicer And more accurate too. If the data structure was complex then the end result would be extremely confusing. Especially with Purity(1). --- demerphq _{<Elian> And I do take a kind of perverse pleasure in having an OO assembly language...}	[reply] [d/l]