Four things:

1. The way to get the value you want is with ${$h{'word1'}[0]}.
2. If you'd have employed use strict, you'd notice that %h isn't yet defined when you try to grab $h{'word1'}. The value that $h{'word2}[0] currently contains is a reference to undef.
3. You could have confirmed all of this by using Data::Dumper with print Dumper(\%h);.
4. Why are you assigning a reference to an arrayref?

Proper way to do this would be to do:

my %h = (
'word1'=>[2,3],
'word2'=>[undef,3],
'word3'=>[1,2]
);
$h{word2}[0] = $h{word1};
print "@{$h{word2}[0]}\n";
__END__
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A few years ago, I would probably have sat for hours putting slashes and curly braces on and around everything without understanding what I was doing. (Who am I kidding? That's exactly what I did.) Now I let Data::Dumper do the heavy lifting for me.

So my question is how to make that output look normal(like what it's supposed to be) ?

What ARE you expecting $h{word2} to contain, [[2,3],3] or [2,3,3] ?

Does this make you any wiser or perhaps you ought to check out the docs?

#!perl -w
use strict;

my %h = (
word1 =>[2,3],
word3 =>[1,2]
);
$h{word2} = [ $h{'word1'},3],
$h{word4} = [ @{ $h{'word1'} },3],

print $h{'word2'}->[0]->[0], "\n";       # Alternative1
print @{ @{ $h{'word2'} }[0] }[0], "\n"; # Alternative1

print @{ $h{'word4'}}[0], "\n";          # Alternative2
print $h{'word4'}->[0], "\n";            # Alternative2

__OUTPUT__
2
2
2
2
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btw, why when i change the code to :


my %h = (
word1 =>[2,3],
word2 =>[1,3],
word3 =>[1,2]
);
$h{word1} = [ $h{word2},$h{word3}];
$h{word2} = [ $h{word1},$h{word3}];
$h{word3} = [ $h{word1},$h{word2}];

print @{ @{ $h{'word3'} }[0] }[0], "\n";
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it gives me out the output : ARRAY(0x8064e68)

And, how can i see this in normal now ?

Let's look at your code with some hand calculations thrown in for fun.

#!/usr/bin/perl

my %h = (
word1 =>[2,3],
word2 =>[1,3],
word3 =>[1,2]
);
$h{word1} = [ $h{word2},$h{word3}]; # [[1,3],[1,2]]
$h{word2} = [ $h{word1},$h{word3}]; # [[[1,3],[1,2]],[1,2]]
$h{word3} = [ $h{word1},$h{word2}]; # [[[1,3],[1,2]],[[[1,3],[1,2]],[1
+,2]]]

print @{ @{ $h{'word3'} }[0] }[0], "\n";
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If you look at the data above, you'll see that you're dereferencing the structure twice. Well, when looking at the zeroeth element, you'll notice that your print statement above gives a reference to an array, specifically [1,3].

To print it, you will need to deref it one more time.

print @{ @{ $h{'word3'} }[0] }[0]->[0], "\n"; # prints "1"
print @{ @{ $h{'word3'} }[0] }[0]->[1], "\n"; # prints "3"
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When in doubt, walk through your data by hand; use Data::Dumper; inspect things.

Hope this helps,

-v
"Perl. There is no substitute."

it should contain [[2,3],3].

my %h = ();
$h{'word1'} = [2, 3];
$h{'word2'} = [\${'word1'}, 3];
$h{'word3'} = [1, 2];
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