each returns a list. $key is now always 2, unless it's 0.

Not so. each is context sensitive as are most things in Perl (you knew that, silly :-)

each HASH

When called in list context, returns a 2-element list consisting of the key and value for the next element of a hash, so that you can iterate over it. When called in scalar context, returns only the key for the next element in the hash.

Actually there is an interesting point here, iirc when you do a Tie::Hash implementation the EACH() sub only returns the key. Perl then automatically follows with a FETCH() to get the value (and I think it does so regardless of the context as well that the each keyword is used in). This is a bit annoying as often in this situation you need to do the same work to get the key or the value and finding one gives you the other. (You can play games to optimise this but its still annoying.)

Oh - try seeing what the stringification of %foo is, even when it's empty. It's not what you think.

I would have thought it would be false when the hash is empty, and suprise suprise it is. :-)

The only change Zaxo needed to make to his code was as you pointed out to change the %val to %foo. Your points about strictures etc is good of course :-)

my %foo;
@foo{qw/ foo bar baz /} = 1 .. 3;
printf "%%foo = %s { %s } = ( %s )\n",\%foo,scalar %foo,
       join(",",map "$_ => $foo{$_}",keys %foo);
while (%foo) {
    my $key = each %foo;
    my $val = delete $foo{$key};
    printf "%s => %s is gone.\n", $key, $val;
    printf "%%foo = %s { %s } = ( %s )\n",\%foo,scalar %foo,
           join(",",map "$_ => $foo{$_}",keys %foo);
}
[download]

%foo = HASH(0x1ab298c) { 2/8 } = ( foo => 1,baz => 3,bar => 2 )
foo => 1 is gone.
%foo = HASH(0x1ab298c) { 1/8 } = ( baz => 3,bar => 2 )
baz => 3 is gone.
%foo = HASH(0x1ab298c) { 1/8 } = ( bar => 2 )
bar => 2 is gone.
%foo = HASH(0x1ab298c) { 0 } = (  )
[download]

---
demerphq

_{<Elian> And I do take a kind of perverse pleasure in having an OO assembly language...}

---

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