--- Martin van-Eerde <[EMAIL PROTECTED]> wrote:
> could you walk me through @h{@vars} = ()
> I think it means many keys of the hash will be assigned an
> undefined list.
> I dont understand the @ meaning array in @h !!
> > my %h;
> > @h{@vars} = ();
> > if (keys %h != @vars) { $youlose = "yes" }
The lexical symbols in Perl tend to tell the parser what sort of value
to expect when it's done parsing the line. That's probably a horrible
oversimplification, but it's good for this point.
In other words, when you look up a value in a two-dimentional array,
your final value is going to be a scalar, so you use a $ even though
you're referencing an array, like this: $array[$ndx1][$ndx2]
In the example above, %h is actually a hash, but an entire array of
keys are being set (with undef's) at once, so it's an array assignment
to the hash keys: @h{@vars} = ();
You could say
for (@vars) {
$h{$_} = undef;
}
to accomplish much the same thing, but doing it at once is much easier
once you understand what's going on.
Does that help?
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