Re^2: Decimal Array range

[Gulliver]

I didn't realize you could assign to $_ inside a foreach loop and it will change the scalars in the list.

[bart]

In foreach, the loop variable (default $_) is an alias to the original value. That means that changing the value will change the original.

my $x = 100;
my @y = (10, 20, 30);
foreach ($x, @y) {
    $_ *= 2;
}
local $" = ", ";
print "\$x = $x\n\@y = (@y)\n";

# or:
foreach my $n ($x, @y) {
    $n *= 2;
}

Ditto in the block or expression for map and grep ($_ only).

map { $_ *= 2 } $x, @y;

grep { $_ *= 2 } $x, @y;

BTW parameters to subs are aliases too, so if you change them in @_, you'll modify the originals too:

sub double {
    foreach(@_) {
        $_ *= 2;
    }
}

double($x, @y);