each() on arrays

With the fairly new Perl 5.12, each() now accepts an array, as opposed to only a hash.

each returns a 2 element list, containing the key and value for the next element in a hash, and now, in an array as well. In addition to the usual:

my %hash = (
  foo => 12,
  bar => 42,
);

while( my($key, $value) = each(%hash) ) {
  print "$key => $value\n";
}

we can also do this:

my @array = ('a' .. 'z');

while( my($index, $element) = each(@array) ) {
  print "$index: $element\n";
}

The index is the key, and the element itself is the value. This means we can do things like:

while( my($i, $e) = each(@array)) {
  print "\$array[$i] = $e\n" if $e eq 'm';
}

instead of manually keeping count:

my $i = 0;

for my $e(@array) {
  if($e eq 'm') {
    print "\$array[$i] = $e\n";
  }
  $i++;
}