Apple IIe - Page 53

Applesoft BASIC Programming 53
numeric. However , some programs require that hundreds or
even thousands of variable names be used.
Obviously, the use of thousands of individual variable names
could prove extremely cumbersome. To overcome this problem ,
BASIC allows
the use of subscripted variables. Subscripted
variables are
identified with a subscript, a number appearing
within parentheses immediately after the variable name. An
example of a group of subscripted variables is given below :
A(O), A(1), A(2), A(3), A(4), .. . , A(100)
Note that each subscripted variable is a unique variable. In other
words , A(O) differs from A(1), A(2), A(3), A(4), etc.
Subscripted variables
should be visualized as an array (or table).
In
our previous example , the data contained in the array defined
by A would consist of one row with 101 columns in it. Such an
array is a single-dimension array.
In
Applesoft BASIC, arrays of up to eleven*elements can be used
as needed in a program. Arrays which contain more than eleven
elements must first be identified via the Dimension (DIM)
statement. When an array is dimensioned , BASIC will reserve an
area
in memory for that array's elements . The following
Dimension statement will dimension a numeric array of 16
elements.
100
DIM B(15)
More than one array can be defined with a single DIM
statement. This is shown in the example below :
100
DIM Z(S ,2), B(100), C(2,3)
*An array of eleven elements would contain the subscripts 0
through 10 inclusive. For example , an array dimensioned as A(10)
would have eleven elements A(O) through A(10) inclusive.