Hi Nora,
On Friday 30 Apr 2010 09:55:33 HACKER Nora wrote:
> Hi,
>
> For calling subroutines and passing arguments on I use e.g.
>
> my ( $var1, $var2 ) = @_;
>
> If I have only one argument, this is also ok:
>
> my ( $var1) = @_;
>
> But why does
>
> my $var1 = @_;
>
> not work?
Because the lack of parenthesis signifies that the right-hand-side will be
done in scalar context. As a result it is equivalent to:
my $var1 = scalar(@_);
Which is the length of the @_ array (which sometimes have some valid uses if
you're checking for optional arguments but otherwise not what you want here.).
If you do:
my ($var1) = @_;
You're doing list assignment and, as a result, you assign $var1 to the $_[0]
and don't make use of $_[1], $_[2], $_[3], etc., which may or may not exist.
> In 'perldoc perlsub' I read that I only have to use
> parentheses when defining more than one variable.
Where do you see that written?
Regards,
Shlomi Fish
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