Commodore Plus 4 - Cassettes

32 The BASIC Language
element of the array by giving the array variable name and the subscripts in the
array where the element is located.
The DIM command names the array and defines the number of elements in the
array. An array can have one, two, or more dimensions. If you use an array
element without first DIMensioning the array, the computer gives the array the
default number of elements (11).
You cannot change the dimensions of an array after you have DIMensioned it,
or after you have accepted the default dimensions. If you DIM the array after you
have used it, or try to reDIM the array, the program is aborted and the error
message REDIM'D ARRAY is displayed.
The first element in any dimension of an array is numbered 0, not 1. This means
that an array dimensioned as (5,3) is actually 6 by 4. When you figure the number
of elements in an array, add 1 to each dimension, then multiply the results of the
additions. For example, if the array is dimensioned DIM K(2,4), the array
contains (2 + 1) * (4 + 1) =-15 elements.
Parameters: array name (subscripts), array name (subscripts), etc.
The default number of elements is 11 (0-10).
1. The array name is a variable that follows standard variable rules. Arrays
containing text elements must have text-string variable names (e.g., A$). Arrays
containing numeric elements must have a numeric variable name.
2. The subscripts set the number of elements in each dimension of the array.
You can define more than one array in a DIM command. Separate multiple
array dimensions with a comma.
You can use arrays with more than two dimensions by supplying additional
subscripts in the dimension command. For example, to DIMension a four-
dimensional array, you can use DIM A(2,2,3,2).
Examples: 10 DIM G(9) Defines a one-dimensional array with ten
elements.
20 DIM G$(3,5) Defines a two-dimensional text array with 24 ele
ments (3+1 rows times 5+1 columns).
30 DIM H(2,3,4) Defines a three-dimensional array with 60 elements
(2+1 times 3+1 times 4+1).
90 PRINT G$(2,2) Prints the element at row 2, column 2.
100 INPUT A(3) INPUTs a value for element 3 in array A. Since
array A has not been defined in a DIM command,
it is given the default number of elements (11).
DIRECTORY Abbr. diR
DIRECTORY Ddrive, Uunit, file name
Displays the following information about the contents of a disk: