Just ….

select column_name
,      case data_type 
          when 'NUMBER' then data_type||' ('||data_precision || case when data_scale != '0' then ','||data_scale 
                                                                                else '' 
                                                               end ||')'
          when 'VARCHAR2' then data_type||' ('||data_length||' '||case char_used 
                                                                    when 'B' then 'Byte'
                                                                    when 'C' then 'Char'
                                                                 end ||')'
          when 'DATE' then data_type
       end           datatype
,      case nullable when 'N' then 'Not Null' else '' end nullable  
from user_tab_columns 
where table_name = 'MMK_MIXMATCHES' 
order by column_id;