Uri Guttman wrote:
>>>>>> "SB" == Steve Bertrand <st...@ibctech.ca> writes:
>
> SB> $user_ref->{$username}{payment} += $payment ||= $payment;
> SB> $user_ref->{$username}{amount} += $amount ||= $amount;
>
> assuming no entries in payment or amount, you don't need the ||= at
> all. += will work on an undef (or non-existing hash) value and coerce it
> to 0 and then add the number. it will not trigger warnings as this is a
> useful case of ignoring undef values. .= (append string) also doesn't
> trigger warnings for the same reason.
>
> perl -lwe 'my %x; print( $x{y} += 3 )'
> 3
>
> perl -lwe 'my $x ; print( $x .= "cd" )'
> cd
>
> perl does all sorts of little things like that. read more about
> autovivication in my article:
>
> http://sysarch.com/Perl/autoviv.txtI read this twice this afternoon. Just now I'm reviewing code that was causing me subtle grief a few weeks ago that I need to perform a translation from one storage format to another. I found a line that started like this: next if ! exists *insert_hash_with_complex_data* heh. Between the books, practical playing, and this list, I'm thinking that I like programming Perl nearly as much as I enjoy engineering the network! Steve
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