use strict;
my $var = 0;   if ( $var ) { print "$var True\n"; } else { print "$var False\n"; }
undef $var;    if ( $var ) { print "undef True\n"; } else { print "undef False\n"; }
my $var1 = '';  if ( $var1 ) { print "'$var1' True\n"; } else { print "'$var1' False\n"; }
my $var2 = "";  if ( $var2 ) { print "\"$var2\" True\n"; } else { print "\"$var2\" False\n"; }
		my $var3 = '0'; if ( $var3 ) { print "\t'$var3' True\n"; } else { print "\t'$var3' False\n"; }
		my $var4 = "0"; if ( $var4 ) { print "\t\"$var4\" True\n"; } else { print "\t\"$var4\" False\n"; }
		if ( $var4 == 0 ) { print "\t\"\$var4\" True\n"; } else { print "\t\$var4\" False\n"; }
		if ( $var4 eq '0' ) { print "\t\"\$var4\" True\n"; } else { print "\t\"\$var4\" False\n"; }
		print "\t","\"\$var4\" has length of ",length($var4)," and ASCII value of ",ord($var4),"\n";
my $var5 = '1'; if ( $var5 ) { print "'$var5' True\n"; } else { print "'$var5' False\n"; }
my $var6 = "1"; if ( $var6 ) { print "\"$var6\" True\n"; } else { print "\"$var6\" False\n"; }
my $var7 = 1;   if ( $var7 ) { print "\"$var7\" True\n"; } else { print "\"$var7\" False\n"; }

##</code><code>##

0 False
undef False
'' False
"" False
        '0' False
        '0' False
        "$var4" True
        "$var4" True
        "$var4" has length of 1 and ASCII value of 48
'1' True
"1" True
"1" True