On Mar 6, Derrick Wippler said:
>Can anyone tell me why " print $rec->[4] " prints
>but print "$recs[0]->[4] does not print a thing ?
This is a scoping issue.
> my @recs;
> my $sql = shift;
> my $st = $db->prepare($sql);
> my $rc = $st->execute(@_);
> my $rec;
>
> while ($rec = $st->fetchrow_arrayref) {
Here you are SETTING the $rec variable each time. This while loop is
going to end when $st->fetchrow_arrayref returns false (probably undef),
so at that point, $rec will be undef.
> print @$rec,"\n";
> print "|$rec->[4]|\n";
> push @recs, $rec;
You are pushing $rec to the array, but $rec is not SCOPED TO THIS BLOCK,
it is scoped to the outer block. When you change it outside the block,
the value you pushed to @recs changes too. Since @recs holds $rec, which
is a reference, when $rec changes, so does what $recs[$i] refers to.
$x = "japhy";
$y = \$x;
$x = "jeff";
print $$y; # jeff
Your solution is to remove the 'my $rec' from outside the while loop, and
place it in the conditional:
while (my $rec = $st->fetchrow_arrayref) { ... }
or, in a slightly clunkier way, leave the 'my $rec' where it is and do:
while ($rec = ...) {
push @recs, [ @$rec ];
}
[ @$rec ] means "dereference the array reference in $rec, and then make an
anonymous array reference with its contents". That copies (a
"shallow" copy) $rec. But it's ugly, too, and doesn't work for
multidimensional structures.
--
Jeff "japhy" Pinyan [EMAIL PROTECTED] http://www.pobox.com/~japhy/
RPI Acacia brother #734 http://www.perlmonks.org/ http://www.cpan.org/
** Look for "Regular Expressions in Perl" published by Manning, in 2002 **
<stu> what does y/// stand for? <tenderpuss> why, yansliterate of course.
[ I'm looking for programming work. If you like my work, let me know. ]
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