128 мODE бY мARK йORDAN тHE EASIEST OF ALL бASIC COMMANDS TO LEARN TO USE IS пRINT. иN FACT, IT'S SO EASY TO USE, EVEN SEASONED PROGRAMMERS MAY FORGET THAT IT HAS A SOPHISTICATED YOUNGER SIBLING: пRINT уSING. бUT, WHY BOTHER LEARNING A NEW COMMAND WHEN YOU'VE ALREADY GOT ONE THAT DOES ITS JOB QUITE WELL? и MEAN, WHAT CAN'T пRINT DO? бY ITSELF, LOTS. вHEN YOU WANT TO FORMAT COLUMNS OF TEXT OR NUMBERS, ESPECIALLY NUMBERS, пRINT HAS TO LABOR. фOR INSTANCE, TO PRINT A NEAT COLUMN OF DOLLARS AND CENTS USING пRINT, YOU HAVE TO DO SOMETHING LIKE THIS: принт лефт$(" "+стр$(абс(нумбер))) +"."+стр$(нумбер-абс (нумбер)) вHEREAS пRINT уSING WOULD HANDLE THE SAME SITUATION LIKE THIS: принт усинг "####.##";нумбер аLSO, пRINT уSING CAN FLOAT A DOLLAR SIGN ALONGSIDE THE NUMBER (OR MOVE IT TO THE LEFT POSITION), PLACE COMMAS IN SPECIFIED LOCATIONS, USE DOTS (PERIODS) AS COLUMN LEADERS (E.G., сMITH......$347.21), INCORPORATE STRINGS READILY (CENTERED, LEFT- OR RIGHT-JUSTIFIED) AND MORE. тHE MAIN REASON пRINT уSING GETS OVERLOOKED IS BECAUSE IT'S JUST ABOUT THE MOST POORLY DOCUMENTED COMMAND IN THE уSER'S гUIDE. иTS THREE-AND-A-HALF PAGES OF EXPLANATION DO LITTLE TO HELP, SO и'LL TRY TO REMEDY THAT RIGHT NOW. пUTTING пRINT уSING TO вORK тHE BIG DIFFERENCE BETWEEN пRINT AND пRINT уSING IS WHAT'S CALLED THE "FORMAT LIST." тHIS IS NOTHING MORE THAN THE PREDEFINED OUTPUT PATTERN YOU WANT. лET'S DISSECT THE FOLLOWING STATEMENT PIECE BY PIECE AND HAVE A LOOK. принт усинг "#####" ; 135 1. тHE FIRST WORD, PRINT, IS THE SAME AS IN THE PLAIN OL' пRINT STATEMENT. 2. бETWEEN THE KEYWORDS PRINT AND USING YOU HAVE THE OPPORTUNITY TO DIRECT YOUR RESULTS TO A FILE IF YOU WANT TO, SUCH AS A PRINTER FILE OR DISK FILE. ыOU DO THIS THE SAME WAY YOU DIRECT OUTPUT TO ANY DEVICE, WITH THE POUND SIGN AND A LOGICAL FILE NUMBER. тHUS, IN PRINT #2, USING THE OUTPUT IS SENT TO FILE 2. 3. нEXT COMES THE KEYWORD усинг. 4. аN OPENING QUOTE AND THE FORMAT LIST COME NEXT. тHE LIST MUST BE WITHIN QUOTES UNLESS YOU PREDEFINE A STRING AS YOUR FORMAT LIST. иF YOU USE A STRING, YOUR FORMAT LIST MIGHT TAKE THE FORM: принт усинг ф$ ; 135. 5. нO MATTER WHETHER YOU ELECT TO PREDEFINE THE FORMAT LIST, OR DO IT WITHIN THE пRINT уSING STATEMENT, IT'S WHAT'S BETWEEN THE BUNS (I.E., QUOTES) THAT MATTERS. иN OUR MODEL, THE FORMAT LIST CONSISTS OF FIVE POUND SIGNS (#####). тHESE TELL THE COMPUTER THAT THE PRINTING COLUMN WIDTH IS FIVE CHARACTERS WIDE. иF YOU'RE PRINTING NUMBERS, пRINT уSING WILL RIGHT-JUSTIFY THE OUTPUT, PRINTING TWO SPACES THEN THE NUMBER 135. тHIS WAY NUMBERS ARE ALWAYS LINED UP ON THE RIGHT, MAKING THE CREATION OF COLUMNS A SNAP. вE'LL DISCUSS THE FORMAT LIST MORE IN A MINUTE. 6. тHE END-QUOTE. нO SURPRISE; IT TERMINATES THE FORMAT LIST.7. тHE SEMICOLON IS NEEDED TO SEPARATE THE FORMAT LIST FROM THE PRINT LIST--A NECESSARY FORMALITY. 8. тHE PRINT LIST. тHIS IS WHAT YOU WANT PRINTED. тHE EXAMPLE ABOVE SHOWS A SINGLE ITEM, THE NUMBER 135; BUT THE PRINT LIST CAN BE AS MANY ITEMS AS YOU WISH, BOTH TEXT AND NUMERIC VALUES, CONSTANTS AND VARIABLES. ыOUR ONLY GRAMMATICAL REQUIREMENT IS TO SEPARATE EACH WITH A COMMA, LIKE THIS: принт усинг "#####" ; 135,нм еACH SUCCEEDING COLUMN BEGINS WHERE THE PRECEDING ONE ENDS. тHEREFORE, IF YOU SET YOUR FORMAT LIST FIVE PLACES WIDE (FIVE POUND SIGNS) YOUR OUTPUT COLUMNS WILL BEGIN EVERY FIVE SPACES. тHUS IF нм ABOVE EQUALED 15893, THE OUTPUT WOULD LOOK LIKE THIS: 13515893. тO CORRECT THIS PROBLEM AND KEEP COLUMNS SEPARATE, YOU SIMPLY WIDEN THE FORMAT LIST. дIGGING дEEPER тHAT'S A QUICK OVERVIEW. нOW LET'S DIG INTO THE DEPTHS OF THAT FORMAT LIST. бESIDES THE POUND SIGN, YOU HAVE EIGHT OTHER SYMBOLS AT YOUR DISPOSAL. еACH OF THESE TELLS пRINT уSING TO DO SOMETHING A LITTLE DIFFERENTLY WITH THE PRINT LIST. * пOUND (#) аS MENTIONED, THIS SIMPLY RESERVES A PLACE FOR OUTPUT. *пLUS (+) пLACING A PLUS SIGN AT THE BEGINNING OF YOUR FORMAT LIST WILL CAUSE ALL POSITIVE NUMBERS TO BE PRECEDED BY A PLUS (+). пLACING THE PLUS SIGN AT THE END OF THE FORMAT LIST WILL CAUSE A PLUS SIGN TO PRINT AFTER POSITIVE NUMBERS. *мINUS (-) тHIS WORKS LIKE THE ABOVE, ONLY IT ATTACHES MINUS SIGNS TO NEGATIVE NUMBERS. (вHEN THIS IS USED, POSITIVE NUMBERS DO NOT RECEIVE PLUS SIGNS.) *дECIMAL (.) пLACING A PERIOD IN YOUR FORMAT LIST EFFECTIVELY TELLS YOUR ц-128 HOW MANY DIGITS TO THE RIGHT OF THE PERIOD YOU WANT DISPLAYED. фOR EXAMPLE, принт усинг "####.##" ; монеы WOULD PRODUCE 78.00 IF монеы EQUALED 78. тHIS ARRANGEMENT IS HANDY FOR PRINTING A COLUMN OF FINANCIAL VALUES (DOLLARS AND CENTS). *дOLLAR ($) тHIS SYMBOL (THAT FAVORITE OF аMERICANS EVERYWHERE) WILL AUTOMATICALLY OUTPUT A DOLLAR SIGN WITH ALL NUMERIC VALUES. ыOU CAN HAVE A FLOATING DOLLAR SIGN (ONE THAT ALWAYS APPEARS IMMEDIATELY TO THE LEFT OF THE NUMBER) BY PLACING IT IN THE SECOND PLACE (LIKE THIS: "#$####.##"). лOCATING IT ELSEWHERE WILL FORCE IT TO APPEAR WHERE YOU PLACE IT WITHIN THE FORMAT LIST. *цOMMA (,) тHE COMMA SIMPLY ALLOWS YOU TO FORCE A COMMA WHEREVER YOU WANT IN THE FORMAT FIELD. тHEREFORE, TO PUT IT BETWEEN THE HUNDREDS AND THOUSANDS PLACE, YOU'D PLACE IT BETWEEN THE THIRD AND FOURTH POUND SIGNS TO THE LEFT OF THE DECIMAL, AS IN "###,###.##".*уP аRROWS (^) фOUR UP-ARROWS IN THE FORMAT FIELD WILL CAUSE THE RESULT TO BE PRINTED IN SCIENTIFIC NOTATION. *еQUAL (=) тHIS SYMBOL PLUS THE NEXT ONE DEAL ONLY WITH STRING OUTPUT. тHE EQUAL SIGN (=) CAUSES THE TEXT TO BE CENTERED WITHIN THE FORMAT FIELD. *гREATER THAN (>) тHIS SYMBOL CAUSES TEXT TO BE RIGHT-JUSTIFIED RATHER THAN ITS DEFAULT OF LEFT-JUSTIFIED. сOME яUIRKS & PUDEFаNY SYMBOLS PLACED BETWEEN THE QUOTES IN THE FORMAT LIST COUNT TOWARDS THE OUTPUT COLUMN WIDTH, NOT JUST THE POUND SIGNS. фRACTIONS ARE AUTOMATICALLY ROUNDED. ыOU CANNOT USE THE SEMICOLON AFTER A пRINT уSING TO KEEP THE CURSOR IN PLACE LIKE YOU CAN WITH пRINT. иF YOUR OUTPUT EXCEEDS THE PLACES PRESERVED IN THE FORMAT LIST, YOU'LL SEE STARS (ASTERISKS, ACTUALLY). вITH TEXT STRINGS, THE STRING IS TRUNCATED--THAT IS, CHOPPED OFF--WHEN IT EXCEEDS THE COLUMN WIDTH. а RELATED COMMAND, пудеф, ALLOWS YOU TO CHANGE THE FILLER CHARACTER (WHICH DEFAULTS TO A BLANK SPACE) TO WHATEVER YOU WANT. тHIS ALLOWS FOR NEAT LISTS THAT PRINT WITH PERIODS BETWEEN COLUMNS. хERE'S A SAMPLE: пудеф ".":принт усинг "######.##"; наме$,амоунт иF NAME$ = "бOB" AND амоунт = 13.72 THE OUTPUT WOULD LOOK LIKE THIS: бOB....13.72 пудеф ALSO ALLOWS YOU TO CHANGE THE COMMA CHARACTER, THE DECIMAL POINT, AND THE DOLLAR SIGN. сEE THE PROGRAM BELOW (AND YOUR уSER'S гUIDE) FOR MORE DETAILS. иT'S TOUGH IN THIS LIMITED SPACE TO SAY ALL и'D LIKE TO ABOUT пRINT уSING. тHAT'S WHY и'VE INCLUDED THE SHORT PROGRAM, принт 128 моде. рUN IT AND YOU'LL GET A GOOD IDEA OF пRINT уSING'S VALUE.