in reply to 'my' headache...why doesn't this work?

The left side of the for-Statement is executed multiple times, so with my, $columnsum seems to become a local variable in the for-block, although use strict doesn't complain.
Try 
my $columnsum = 0; 
$columnsum += $_->{columns} for @data;
print $columnsum;

[download]
and everything seems to be fine.

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Re: Re: 'my' headache...why doesn't this work?
by S_Shrum (Pilgrim) on Apr 05, 2002 at 10:11 UTC

    That's works....I guess I understand the FOR issue. Still would'a thunk that strict would have gagged on it.

    ======================
    Sean Shrum
    http://www.shrum.net

[reply]
      strict is smart enough to detect variables that are not properly declared, but not necessarily to detect variables that are logically misused. In this case, declaring a 'my' variable inside a for loop is perfectly legal (in fact, I do it all the time without thinking much about it), e.g. 
      foreach my $foo (@ary) {
  . . .
}

      [download]
      But for a running summation, of course it's not what you want. So strict doesn't see a problem; although it's misused, the variable is properly declared.
[reply]
[d/l]

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