DIM function

Apart from the DIM array declaration command, there's also a function by the same name that returns information regarding any declared array. It's syntax is:

DIM (arrayname$ [, dimension]) |numeric and it returns the number of elements in the specified dimension of the array arrayname (dimension defaults to 0 if not specified).

If dimension equals 0, DIM will simply return the number of dimensions in the array.

Simple strings are treated as single-dimension character arrays, returning 1 as the number of dimensions and the current string length as the number of elements in dimension 1.
Let's write a little program to illustrate:

10 DIM a(100,10,5)
20 PRINT DIM (a())
30 PRINT DIM(a(),1)
40 PRINT DIM(a(),2)
50 PRINT DIM(a(),3)

which will return:

  3
100
 10
  5

Exercises

1. Use READ and DATA statements to set up an array m$ of twelve strings in which m$(n) is the name of the nᵗʰ month. (Hint: the DIM statement will be DIM m$(12,9). Test it by printing out all the m$(n) (use a loop)).

2. Type:

   PRINT "now is the month of
   ";m$(5);"ing"; " when
   merry lads
   are playing"
   

   What can you do about all those spaces?