#!/usr/bin/perl
use strict;
my $x1 = 1;
my $x2 = 1;


print "\$x1 starts as $x1 and \$x2 starts as $x2.\n";

# method 1
if ($x1++) {
    if ($x2++) {
        print "We incremented \$x1 to $x1 and \$x2 to $x2.\n";
    }
}

undef $x1;
undef $x2;
print "Undefine them both...\n";

#method 2
if ($x1++ && $x2++){
    print "Shouldn't ever get here!\n";
}

print "Now, we incremented \$x1 to '$x1' and \$x2 is still '$x2'.\n";