Sharp PC-1500 - Page 70

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"charact er ar r ay" ) you may also specify the size of the strings, up to a maximum of 80 characters
per string. Creat ing characte r' st ri ng$ of varying si ze s is described in Section B .1 .
To de fin e an array, the DIM {short fo r dimensi on) statement i$ \!$ed. Arrays m uH a l w~ys be
"decla r ed" {define<!) before they arn u sed. ( Not li ke the single·val ue variables we l>ave been us ing.)
The fo rm for the numeric DIMension statement is:
DIM nu meric·variable·name (size}
\•1he re:
nu meric-variable· na r ne is a va ri able name vJh ich conforms to the normal r ules for numer ic
variable names pr eviously discussed.
size is the num b er of storage l ocat i ons and must be a nt.Jmber in the range 0 through 255. Not e
that wh en you specify a n um ber for the size yo u get one more locat ion than you
spec if i~d.
Examp l es of legal nu meric D IM e ns ion sta te ments are :
DI M X 15 )
DIM
AA (24)
DIM 05 (0)
The first statemen t cr eates an ar r ay X with 6 storage locations. The second s.tate me nt creates
an array AA \V i th 25 locations. The t hi rd stater nent c1eates an array wit h one lo catio n and is
actually raiher silly since {for n umb ers at least), it is the same as dec laring a sing l~ · value numeric
variable.
It
is impo rtant to know that an array -v ari ab le X and a vari ab le X are separat e and distinct to
SHARP. The fi r st X denotes a series of numeric storage l oc ati ons, and the se cond a single and
different l ocat i on.
Now tha t you know how to create arrays, you might be wo n de ring hO\'V it is that we r efe r to
each stor1:19e l ocat io n. Since the entire group has on ly one name . the way in which we r efer to
a single l ocation (.called an "elerr-ent") is to follow the group name with a number in pa r ent hese s.
This
numbe r is cal l ed a "sub.scri pt" . Thus, for exampl e, to st ore the number 8 into the fifth
clement of our array X (declar ed previously) \VC would v1 ritc:
x (4) = 8
If the use of 4 is p1.1 7.Z ling, r emember tha t the numberi ng of el ements beg in s at ze ro and cont inues
through
the si te number de cla red in the DIM sta t~mcn t .
T he real po\\le·r of arrays lies in the ab ili ty to use an expressi on or a variable n ame as a sub·
script. Fof example. to create a table containing the squares of the numbers 0 to 9 \\'e could
wr i te the fo ll owing statements:
10 DIM SO (9)
20 FOR I = 0 TO 9
30 SO (I) = I* I
40 NEXT I
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