use strict; use warnings ;

  foreach my $z ('0', '0000', '+0', '-0', ' 0', '0 ', '0E0') { try($z) ; } ;

  sub try {
    my ($z)  = @_ ;
    my $bool = $z      ? 'True' : 'False' ;
    my $zero = $z == 0 ? '=='   : '!=' ;
    printf "%7s is %5s and %2s 0\n", "'$z'", $bool, $zero ;
  } ;