Re: Always Follow Up on Warnings

[blakem]

I've been known to rant about uninitialized warnings before... Here is one nice idiom for "cleaning" a series of undefined values.

$_ = '' for grep !defined, ($x,$y,$z);

Try the following code with and w/o this clensing line:

#!/usr/bin/perl -wT
use strict;

my ($x,$y,$z) = (undef,'hello',undef);

# undef "clensing" idiom
$_ = '' for grep !defined, ($x,$y,$z);

print "x='$x' y='$y' z='$z'\n";

-Blake

[crazyinsomniac]

Speaking of idioms, I never use one for this type problem, but here is a more idiomatic solution (if u ask me)

#!/usr/bin/perl -wT
use strict;

my ($x,$y,$z) = (undef,'hello',undef);

$_ ||='' for $x,$y,$z;

print "x='$x' y='$y' z='$z'\n";

## OR EVEN (most idiomatic imho)

$_||='' for my($a,$b,$c)=(undef,9,undef);

print "a='$a' b='$b' c='$c'\n";

Happy Coding!

 


______crazyinsomniac_____________________________ Of all the things I've lost, I miss my mind the most. perl -e "$q=$_;map({chr unpack qq;H*;,$_}split(q;;,q*H*));print;$q/$q;"

[redsquirrel]

The problem with $_ ||= '' is that it turns 0's into ''. defined is much less cool, but definitely more effective.

--Dave

[$code or die]

I can't wait until we have $_ //= ''

In Perl 6, this would probably be written:

($x, $y, $z) ^//= '';

Now that is *really* sweet.

___ Simon Flack ($code or die)
$,=reverse'"ro_';s,$,\$,;s,$,lc ref sub{},e;$,
=~y'_"' ';eval"die";print $_,lc substr$@,0,3;