String Array Notation

String array names end with the $ character. Numeric array names do not have an appended character.

StringArray$()
NumericArray()

DIM String Arrays

Arrays with 11 elements, numbered 0-10 do not need to be dimensioned before use. Arrays with more elements and double-dimensioned arrays must be dimensioned.

 DIM color$(20)

Assign a Value

Assign values to array indices in the same way you assign values to variables, with the = character. The index number appears in the parenthesis. To assign the string "Potato" to index 1 of the array named array$() :

 array$(1) = "Potato"

Filling Arrays

You may fill an array with string literals, string variables, or string expressions.

 array$(1)="Green" 
 array$(2)=upper$("red")+" "+upper$(blue) 
 color$="orange" 
 array$(3)=color$

Filling Arrays from Files

Arrays may be filled by inputting to an array from an open file. In the following demo a file is opened for output and filled with five color names, separated by commas. The file is closed, then opened again for input. The input statement reads items deliminated by commas or CRLFs. Each item in the file is assigned to an array index in a loop.

 open "colors.txt" for output as #f 
 print #f, "red, green, blue, yellow, brown" 
 close #f 
 
 open "colors.txt" for input as #f 
 for i = 1 to 5 
 input #f, col$(i) 
 next 
 close #f 
 
 for i = 1 to 5 
 print col$(i) 
 next

Filling Arrays with WORD$()

An earlier example showed how to fill each array index individually. That requires a lot of typing and many lines of code for larger arrays. It is faster and easier to use a long string to hold the data and use the WORD$() function in a loop to fill the array, like so:

 terms$ = "red green blue yellow brown" 
 for i = 1 to 5 
 col$(i) = word$(terms$,i) 
 next 
 
 for i = 1 to 5 
 print col$(i) 
 next

If the array elements contain more than a single word, use the optional delimiter with the WORD$() function. In the following code, a comma is used to separate items in a string, and then used as the delimiter in the WORD$() function. This allows each array element to contain a string of multiple words.

 terms$ = "bright red,light green,pale blue,sunshine yellow,muddy brown" 
 for i = 1 to 5 
 col$(i) = word$(terms$,i, ",") 
 next 
 
 for i = 1 to 5 
 print col$(i) 
 next

DATA and Arrays

The information to be loaded into an array can be contained in DATA statements. It is then read into a variable with the READ command. The value of the variable is then assigned to the array index. This can also be done in a loop in a similar fashion to reading data from a file or from a large string.

 for i = 1 to 10 
 read val$ 
 col$(i) = val$ 
 next 
 
 for i = 1 to 10 
 print col$(i) 
 next 
 
 data "bright red","light green","pale blue","sunshine yellow","muddy brown" 
 data "pewter","terra cotta","deep purple","gray","tangerine"

Notice that the DATA is READ into a variable. READ will not allow assignment directly to an array.

THE FOLLOWING CODE WILL HALT WITH A SYNTAX ERROR WHEN YOU TRY TO RUN IT

 for i = 1 to 10 
 'SYNTAX ERROR: 
 read col$(i) 
 next 
 
 for i = 1 to 10 
 print col$(i) 
 next 
 
 data "bright red","light green","pale blue","sunshine yellow","muddy brown" 
 data "pewter","terra cotta","deep purple","gray","tangerine"