Radio Shack TRS-80 Model III - Page 110

TRS-80 MODEL III
Variable
Names
In
BASIC
,
variables are represented by names
. Variable names
must begin with a
letter,
A through Z. This letter
may be
followed
by one more character
—
either a
digit
or a letter.
For example
AM
A
A1 B1
AB
are
all
valid and distinct variable
names.
Variable
names
may be
longer
than two characters.
However, only the first
two
characters
are
significant
in BASIC.
For example:
SUM
SU SUPERNUMERARY
are all
treated as the
same variable by BASIC.
Reserved
Words
Certain combinations
of letters
are reserved as BASIC
keywords
, and cannot be used
in variable
names . For
example:
OR LAND
LENGTH
MIFFED
cannot
be used as
variable names,
because they contain the
reserved of
OR, AND, LEN,
and IF, respectively.
See the
Appendix for a list
of reserved words.
Simple and
Subscripted
Variables
All of the
variables
mentioned above
are simple
variables. They
can only
refer
to
one data item.
Variables
may also
be subscripted
so that an
entire list
of data can
be stored
under
one variable
name.
This method
of data storage
is called
an array.
For example,
an
array
named
A may contain
these elements
(subscripted
variables):
A(0)
A(1) A(2)
A(3)
A(4)
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