scalar context _undef == $VAR1 = undef;

list context _undef == $VAR1 = [
          undef
        ];

scalar context zero == $VAR1 = 0;

list context zero == $VAR1 = [
          0
        ];

scalar context empty == $VAR1 = undef;

list context empty == $VAR1 = [];

scalar context nothing == $VAR1 = undef;

list context nothing == $VAR1 = [];