jeffa,
I know you know this, but since you are running off to a rock concert I thought it would be worth while to point out a potential "gotcha" with un-intentional auto-vivication. Of course I have broken it down to an extreme for the sake of the OP.

Say you had a hash set up as: 

my %month_hash = (
    '1' => 'January',
    '2' => 'February',
    '3' => 'March',
    '4' => 'April'
);

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And since a hash doesn't come out in any meaningful predictable order - you created an array to get the order you wanted: 
my @order = (1 .. 4);

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Finally, for some reason you wanted to create a new array with the month names in it - you might try: 
my @months = @month_hash{@order};
print $_,$/ for @months;

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This would work unless one of your keys was deleted as such: 
delete $month_hash{3};
my @months = @month_hash{@order};
print $_,$/ for @months;

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You would then get an error about an uninitialized value. This happens because the hash slice creates a new key for '3' and sets its value to undef.

Cheers - L~R

In reply to Re: Re: What is a "slice" ? by Limbic~Region
in thread What is a "slice" ? by Hayl_

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