my $var = "xxx\n";
my $var="zzz\n" unless defined($var);
print $var;

##</code><code>##

#my $var = "xxx\n";
my $var="zzz\n" unless defined($var);
print $var;

##</code><code>##

"my" variable $var masks earlier declaration in same scope at unlesstest.pl line 2.
Use of uninitialized value in print at unlesstest.pl line 3.

##</code><code>##

Name "main::var" used only once: possible typo at unlesstest.pl line 2.
zzz