my $alphabetised = "1";                # Sets $alphabetised to "1"

until ($alphabetised = "1"){           # Sets it to "1" again
                                       # Succeeds (returns TRUE)
                                       # TRUE before we even begin
                                       # Thus, never executed
};

##</code><code>##

until ($alphabetised == "1"){          # Checks instead of sets
until ($alphabetised eq "1"){          # Checks instead of sets
while ($alphabetised eq "1"){          # while() instead of until()
my $alphabetised = "0";                # Initialize differently