Sharp PC-1403 - Page 87

81
X ( 4) = 8
The fir st s tat ement cr eates an a r ray X with 6 storage lo cation s . Th e se c ond s tatement
creates an a r r ay AA wi t h 2 5 loc atio n s . Th e th i rd stateme nt c r ea t e s a n arr ay with one
loc a t ion a nd is actuall y rat he r s il ly s ince (fo r numbe r s a t l e a s t) , it i s th e sa me as
de cl a ring a singl e -v a lue numeri c v ar i a bl e .
It i s i m po rt an t to know tha t arra y varia b l e X a nd v ar i able X a r e s ep arate , a nd un i q ue t o
SHARP . Th e first X d enote s a s e ries o f numer ic s torage l oc at i o n s, a nd th e s e c ond a
s i ng l e and d i tte r e nt l oc a t io n .
N ow t ha t y o u know h o w to c re at e a rrays , y o u mig h t be w onde r i n g h o w t o re f er to eac h
s t ora g e l oca t i o n . S in ce t he e nti re g r oup ha s onl y on e na m e, t he way i n w h i c h w e re f er
t o a s ingle l oca tion (ca ll ed an "e leme nt ") is to fo llow the group na m e w i t h a number in
paren t he s e s . Th is numb er i s c a lle d " subscript ". Thu s , for ex ampl e , to sto r e th e
numbe r 8 i nto the fi ft h ele ment of our array X ( d e c l ar e d previo usl y), w e wo ul d write :
DIM X( 5)
DIM AA (24)
DIM 0 5 ( 0 )
n u m e ri c-va riable - n a me i s a va r iab le name which co nf o rm s t o t h e n o r mal r u les for
n um er ic va r iable na me s pr ev iou s l y d isc u ss ed .
size is t he num b e r o f sto r a g e l ocat i on s a nd m ust b e a numbe r in t he r ange 0 throug h
255 . Not e t hat when y o u s p eci fy a nu m be r f or the s i ze, y o u g e t one m o r e loc at ion
than y o u s p e c ifi ed .
Examples of leg a l n umer i c DIMension sta t ements are :
Array Variables
For so m e pur pose s , i1 i s u sef u l t o dea l w ith num be r s as an o rg a ni z e d group , s u ch a s a
li st o f scor e s o r a la x ta b l e . In B A S I C t h ese g ro u ps are ca ll ed arrays . An ar ray c an b e
e ither one-dimensional , lik e a l is t , or two-dimensional , l ike a t a bl e .
To d e fi n e an a rray , t he DIM ( short for dimensi o n ) st a te m e nt i s u se d . A r r ays m u st
al w ays be " d e c lar e d " ( d e fined ) be for e th ey are u s e d (n o 1 li k e the s ing l e-valu e
vari able s w e ha ve been u s in g). Th e f orm for t he num er i c DIM e n s ion s tat e m e nt is :
DIM num e ri c - v a r iabl e- n a m e ( s i z e )
wh e r e :
Notes: • Th e f un ct i on s an d B A S I C commands inh ere nt t o th e co mp u t er a r e no t
usa bl e as var ia ble n a m es .
e . g . , P l , I F , TO, O N , S I N, etc.
• Each s im p l e c ha ract e r v ar ia b l e c an ho l d u p t o 1 6 c h a r acte r s an d s y mb o l s.
Concepts and Terms of BASIC