Re^2: Hash problem

You're right about needing to use a reference to an array for assigning to a hash element, but that way of doing it can be rather wasteful. What you are doing with $Tex{$a} = [@bex] is copying the contents of @bex in to another array and then assign a reference to that new array to $Tex{$a}.

You can avoid the unneccesary copying by just taking a reference to the original array

if (!$Tex{$a}){
    $Tex{$a} = \@bex;
}
[download]

Of course, this only works correctly in a loop if the array you are taking a reference to is scoped to the loop. If not, your method is correct.

Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.

Lingua non convalesco, consenesco et abolesco. -- Rule 1 has a caveat! -- Who broke the cabal?

"Science is about questioning the status quo. Questioning authority".

In the absence of evidence, opinion is indistinguishable from prejudice.

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Re^3: Hash problem by ikegami (Patriarch) on Feb 04, 2006 at 02:12 UTC
`\@bex` won't work unless you do `my @bex` in the foreach loop. You mentioned this (in less explicit terms), but I just wanted to be clear. Without the `my`, all values will be references to the same array. In fact, the OP says he's using `[@bex]`, but the symptoms he's describing are those of `\@bex`.	[reply] [d/l] [select]
Re^4: Hash problem by BrowserUk (Patriarch) on Feb 04, 2006 at 02:24 UTC
\@bex won't work unless you do my @bex in the foreach loop. You mentioned this (in less explicit terms), but I just wanted to be clear. The scoping doesn't have to be my, local works just fine too: #! perl -slw use strict; use Data::Dumper::SLC; my %hash; our @array; for my $i ( 0 .. 9 ) { local @array = map{ "$i : $_" } 1 .. 5; $hash{ $i } = \@array; } Dump \%hash, 60; __END__ c:\Perl\test>junk3 { 0 => [ '0 : 1', '0 : 2', '0 : 3', '0 : 4', '0 : 5', ], 1 => [ '1 : 1', '1 : 2', '1 : 3', '1 : 4', '1 : 5', ], 2 => [ '2 : 1', '2 : 2', '2 : 3', '2 : 4', '2 : 5', ], 3 => [ '3 : 1', '3 : 2', '3 : 3', '3 : 4', '3 : 5', ], 4 => [ '4 : 1', '4 : 2', '4 : 3', '4 : 4', '4 : 5', ], 5 => [ '5 : 1', '5 : 2', '5 : 3', '5 : 4', '5 : 5', ], 6 => [ '6 : 1', '6 : 2', '6 : 3', '6 : 4', '6 : 5', ], 7 => [ '7 : 1', '7 : 2', '7 : 3', '7 : 4', '7 : 5', ], 8 => [ '8 : 1', '8 : 2', '8 : 3', '8 : 4', '8 : 5', ], 9 => [ '9 : 1', '9 : 2', '9 : 3', '9 : 4', '9 : 5', ], } [download] The funny thing is that I changed the wording specifically to avoid a correction being required :) Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error. Lingua non convalesco, consenesco et abolesco. -- Rule 1 has a caveat! -- Who broke the cabal? "Science is about questioning the status quo. Questioning authority". In the absence of evidence, opinion is indistinguishable from prejudice.	[reply] [d/l]