Beefy Boxes and Bandwidth Generously Provided by pair Networks
Problems? Is your data what you think it is?

Re: @_ ... side step, use an arrayref

by George_Sherston (Vicar)
on Jun 01, 2002 at 23:45 UTC ( #170950=note: print w/ replies, xml ) Need Help??

in reply to @_ still mystifies me

This seems like reason nr 128 in the series for passing args to subs as references to data structures rather than the structures themselves. In this case an arrayref.

Then you can use the high precedence (logical) Or, ||. Critically, this has higher precedence than =. So $dinner = $ham || $eggs;
means dinner is ham or, if we've got no ham, eggs. As opposed to $dinner = $ham or get('takeaway');
which means dinner is ham, but if we fail to make dinner from ham, we're gonna send out.

As other monks remark, || forces scalar context on the LH operand, so if you pass a three-element array, you'd get '3'. But with an arrayref you're already in scalar context so you don't care.

The only disadvantage is, you don't use @_ explicitly. This is a disadvantage because that was what your question was about!

use strict; use Data::Dumper; my %lexicon = ( foo => 'boink', bar => 'blink', baz => 'squirm', ); sub grop { my $lexlist = shift || [sort keys %lexicon]; print Dumper($lexlist); } grop(['gump','snoop','grock']); grop();
Which produces
$VAR1 = [ 'gump', 'snoop', 'grock' ]; $VAR1 = [ 'bar', 'baz', 'foo' ];

George Sherston

Comment on Re: @_ ... side step, use an arrayref
Select or Download Code

Log In?

What's my password?
Create A New User
Node Status?
node history
Node Type: note [id://170950]
and the web crawler heard nothing...

How do I use this? | Other CB clients
Other Users?
Others rifling through the Monastery: (5)
As of 2015-11-26 01:05 GMT
Find Nodes?
    Voting Booth?

    What would be the most significant thing to happen if a rope (or wire) tied the Earth and the Moon together?

    Results (695 votes), past polls