Atari XL

24
The Ateri XL Handbook
available, but you must set the maximum number
of characters allowed for each string variable
before using the variable. The DIM command
(short for dimension) is used for this:
DIM BONZO$(30)
sets the string variable BONZO$ to have a
maximum length of 30 characters. If you then try
to store more than 30 characters in BONZO$ an
error message will be displayed.
NOTE It is possible to have variables of
different types with the same name,
such as:
NAME = 87.76
NAME$ = "GEORGE WASHINGTON"
The computer will not be confused, but
you might, so be careful!
ARRAYS
Numeric variables (but not strings) may be used in
a special form - an array. In normal use a variable
name represents one stored number. In an array,
the variable name represents a collection of stored
information, with one or more reference numbers
identifying the individual items. An array can be
pictured as a collection of boxes. The table on the
next page is a diagram of an array which uses one
reference number.
The array has 6 elements numbered from 0 to 5.
The array would be used like this:
10 DIM BOXES(5)
20 BOXES{O) = 11
30 BOXES{l) 92.73
40 BOXES(2) = 6