How do I set up a "jagged array" in VBA?

Question

I have a classroom full of kids, each of whom have to list their favorite toys for an assignment. Some kids only list 1 toy whereas others list more.

How do I create a jagged array such that Kids(x)(y)...where x is the number of kids in my class, and y is the list of toys that they list as their favorites?

Answer 1

"Jagged array" is slang for array of arrays. VBA'sVariant data type can contain just about anything*, including an array. So you make an array of type Variant, and assign to each of its elements an array of arbitrary length (i.e. not all of them have to have equal length).

Here's an example:

Dim nStudents As Long
Dim iStudent As Long
Dim toys() As Variant
Dim nToys As Long
Dim thisStudentsToys() As Variant

nStudents = 5 ' or whatever

ReDim toys(1 To nStudents) ' this will be your jagged array

For iStudent = 1 To nStudents
    'give a random number of toys to this student (e.g. up to 10)
    nToys = Int((10 * Rnd) + 1)
    ReDim thisStudentsToys(1 To nToys)

    'code goes here to fill thisStudentsToys()
    'with their actual toys

    toys(iStudent) = thisStudentsToys
Next iStudent

' toys array is now jagged.

' To get student #3's toy #7:
MsgBox toys(3)(7)
'will throw an error if student #3 has less than 7 toys

_{* A notable exception is user-defined types. Variants cannot contain these.}