#!/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";