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Re: perl v5.16 bug?

by tobyink (Abbot)
on Mar 15, 2013 at 23:38 UTC ( #1023795=note: print w/replies, xml ) Need Help??


in reply to perl v5.16 bug?

The problem is that the entire while condition is evaluated every time around the loop, meaning that [@a] is evaluated every time around the loop, yielding a reference to a different anonymous array every time around the loop.

Because you're polling a fresh new array every time around the loop, each's "pointer" for the array is at the beginning every time.

This is the safe way to do it:

while (my ($i, $v) = each \@a) { say "$i: $v"; }

... because you're using a reference to the same array every time around the loop.

package Cow { use Moo; has name => (is => 'lazy', default => sub { 'Mooington' }) } say Cow->new->name

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[abner]: yes. i am familiar with mysql but ignorant about how to get around the fact that placeholders can only represent single scalar values.
[abner]: my $sth = $dbh->prepare(' SELECT * FROM charge WHERE cpt = ?') or die "Couldn't prepare statement: " . $dbh->errstr;
[abner]: what if i want SELECT * FROM charge WHERE col1 = x and col2 = y?
[atcroft]: abner: So you are wanting to do something like my $sth = $dbh->prepare(' SELECT * FROM charge WHERE col1 = ? and col2 = ?;'); $sth->execute(' asdf', 'asdw');?
[atcroft]: (Full disclosure: I may have the idea right but small typographical errors, so please test any code I suggest. :) )

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