You probably used strings in double quotes. Perl interpolates (scalar and array) variables in double quotes. You can
- use single quotes '$LOGIN_INFORMATION = array("guest" => "1234");'
- use the q// operator: q/$LOGIN_INFORMATION = array('guest' => '1234');/
- backslash the dollar sign (and at signs): "\$LOGIN_INFORMATION = array('guest' => '1234');"