Radio Shack TRS-80 User Manual page 127

We
obviously used a
FOR-NEXT
loop
to
READ
10
DATA
elements, and
named
those
elements (or "cells")
in
which
they're stored, A(l) through A(10).
Let's see
if
we
can
PRINT
out the values
in
those array elements.
Type:
200 FOR N =
1
TO
10
210 PRINT
A(N)
220 NEXT
N
. . .
and
RUN.
Aha!
It
works, but
how?
We
read the
DATA
elements
into
an
array called A(L), but printed
them
out of an
array called A(N).
What
gives?
Oh,
nothing,
really.
The
array's
name
is
"A".
The
location of each data element within that array
is
identified
by
the
number which
we
place
inside
the parentheses.
We
can
bring that
number
to inside
the parentheses by
using
any
of our 26
letter variables,
and
can even do
some
simple
arithmetic
inside
those paren-
theses
if
we
wish.
Remember,
though, there
is
only one
array,
and
its
name
is
"A".
Its
elements
are
numbered,
and
called
A-sub (number).
Let's
work some more
on the program.
Type:
170
PRINT
180
PRINT "LICENSE #", "ENGINE SIZE"
210 PRINT N,A(N)
. . .
and
RUN
.
Now
that's
more
like
it.
We
have every
license
number,
every engine
size,
and
are
not
"using
up"
any
of the 26 alphabetic
variables.
Having demonstrated
that point, erase lines 20(5,
210
and
220,
and
type:
10
IN.
"WHICH CAR
'
S
ENGINE SIZE DO YOU WANT
TO
KNOW";W
2 10
PRINT W.A(W)
...
and
RUN.
Some
pure mathematicians
might
insist
on
catling
A{X)
-
A
"OF"
X.
Who
needs that
added
conftision? Best
'teat
you know,
just in
'
*s$&
;
:
M
125