# perl -wle ' %hash = ( key => "" ); if ( exists $hash{key} and defined $hash{key} ) { print "is was da"; } else { print "is nix da"; }  '
is was da
# perl -wle ' %hash = ( key => "" ); if ( $hash{key} and defined $hash{key} ) { print "is was da"; } else { print "is nix da"; }  '
is nix da
#