Sharp PC-1403 - Page 107

10 1
Any one of t he f ollow i ng c h ara c t e rs can be u s e d: A, S , 0 , F , G , H , J , K, L , •, Z , X,
C , V , B , N, M , a nd SPC . N otice t h a t t hese are the k e ys in t h e bo t tom t wo rows of th e
alphabe t ic po rtion o f the key b oa rd .
No t e: To ex e cute t h e p ro g r am , i ns t ead o f t yp i n g RUN 8 0 or GOTO 10 , you need only
p ress the ~ k e y and t hen t h e le tt e r used as a l abe l. I n the ab ov e e x ample ,
pr e ss i ng ~ an d then ' B ' woul d ca u se ' SECOND ' t o app ear on the
displ a y .
Whe n D EF i s u sed to execute a progr am, v ar iables a nd mode se ttin gs are a ff ec te d in
the sam e w ay a s wh e n GOT O is u se d . S ee C h apter 8 fo r d e tail s .
Often you w ill wa n t to store several diff erent programs i n t h e co m p ute r m e mory a l on e
time. (Remembe r th at e a ch must h a ve uniqu e line n umb e rs.) No rmall y , to s tart a
program w i th a RU N or G O TO comma nd , yo u need t o remember the beg in ning line
number of each prog r a m (se e Chapter 8 ) . B u t , there is a n ea sie r way ! You can label
each program with a l e tt er a n d e xecu t e the p ro g ram u si ng o n l y two ke ystrokes. This is
how to label a program and e xecute it us i ng D EF:
No te : Put a label on the f i rs t l i ne o f e ach progra m tha t you wa nt to reference.
The labe l cons i s t s o f a sin gl e characte r in q u o t e s, fo ll owed by a colon ( : ).
10 : " A ": PR I N T " F I R S T "
20: END
3 0 : " B ": PRINT "S ECON D "
40 : END
The DEF Key and Labeled Program s
Thi s ch ap t er d isc u sses the a d d it i onal feat ur e w h i ch c a n e l i mina te unn ecessa ry ty ping-
th e ~\ k e y . (DEF is s ho rt fo r " D EF INE ".)
The c omput er in cl ud es sever a l f eatu r es wh i c h m a k e pro g ra mm i ng more co n ve ni en t b y
re du ci ng t h e nu mb e r of keystrokes r eq u i r ed t o ente r r epe t it i ve m at er i al.
On e such fea ture is in the availability of abbr ev i at i ons for v e rb s a nd c o mmand s ( se e
C h apter 8).
' ' '
CHAPTERS . .
SHORT CUTS . :'
Short Cuts