Re^2: how can i return the common keys from a hash

I am somewhat puzzled by the following DWIM:

in scalar context, each returns the next key of the hash. Why doesn't, then, the assignment "my $m = each %$href" return false if the key is "0"? ie

> perl -wle 'my %a = ( 0 => 1, y => 2, z => 4); while (my $m = each %a
+) { print $m }'
y
0
z
> perl -wle 'my @a = ( 0 => 1, y => 2, z => 4); while (my $m = pop @a)
+ { print $m }'
4
z
2
y
1
> perl -wle 'my @a = ( 0 => 1, y => 2, z => 4); while (my $m = shift @
+a) { print $m }'
>
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Re^3: how can i return the common keys from a hash by imp (Priest) on Aug 05, 2006 at 01:42 UTC
`perl -MO=Deparse -wle 'my %a = ( 0 => 1, y => 2, z => 4); while (my $m + = each %a) { print $m }' BEGIN { $^W = 1; } BEGIN { $/ = "\n"; $\ = "\n"; } my(%a) = (0, 1, 'y', 2, 'z', 4); while (defined(my $m = each %a)) { print $m; }` [download] It checks for defined as the loop condition, not a true value.	[reply] [d/l]
Re^4: how can i return the common keys from a hash by ivancho (Hermit) on Aug 05, 2006 at 02:07 UTC
indeed, as that's what you want in 99% of the cases.. I was mostly pointing out that it's neither logical, nor obvious from docs	[reply]