"List" struct

As 3dsmax doesn't allow for either associative arrays or dynamically-set object properties, it can be difficult to store unstructured, arbitrary variables.

Sometimes you just want to store lists of name/value pairs, to keep track of a few settings throughout your script, without relying on a host of variables, resorting to .ini files, or custom attributes.

Therefore, I set about writing a basic Dictionary, or List struct, similar to VB and other languages.

Example code

Here's a really basic example of storing 5 named variables within a List:

names = #("five", "four", "three", "two", "one")
values = #(5,4,3,2,1)
lst = List()

for i = 1 to 5 do lst.addItem names[i] values[i]

So let's get some data back out:

lst.getValue "two"
-- 2

lst.getIndex "two"
-- 4

-- #(5, 4, 3, 2, 1)

Or print the whole lot:

lst.print() -- unsorted

five:	5
four:	4
three:	3
two:	2
one:	1

How about some sorting:

lst.sort() -- by name, alphabetically

five:	5
four:	4
one:	1
three:	3
two:	2

lst.sort field:#value -- by value

one:	1
two:	2
three:	3
four:	4
five:	5

As you can see, it's pretty straightforward stuff!

Properties and Methods


  • <array> items <name> <value> – the key/value pairs.
    • Names can be a #name, "string", or even an index
    • Values can be any MaxWrapper value (i.e. anything)


  • <ListItem> addItem <name> <value> – adds an item to the List, and if it already exists
  • <ListItem> setItem <name> <value> – synonym for the above


  • <value> getValue <name> – returns the value of the named item
  • <index> getIndex <name> – returns the index of the named item
  • <name> getName <value> – returns the name of the first item that matches the supplied value
  • <ListItem> getItem <name> – returns the List item corresponding to the supplied name (typically, you wouldn't use this, as you know the name component already, it's just included for completeness)
  • <array> getItems() – returns all items as an array of ListItem structs
  • <array> getNames() – returns all names as an array
  • <array> getValues() - returns all values as an array

Clear or delete

  • <array> clear() – clears the lit of all items, and returns the empty ListItems array
  • <boolean> deleteItem <name> – deletes the named item from the list, and returns it
  • <boolean> deleteIndex <index> – deletes the item at the index, and returns it


  • <array> sort field:<name> order:<name> func:<function> – sorts the list in a variety of ways, even supply a comparison function (see the max help on qsort)
  • <string> print() – prints the List items to the Listener

Next version

Possible improvements in the next version might be:

  • .ini file integration, with save() and load() methods
  • Support for hierarchical Lists, perhaps getValue #(#parent, #child, #grandchild, …)


Download List.struct.ms here.

1 Comment

  1. diffx

    Hey Dave,

    Thanks for saving me a lot of time. I was thinking of a better way to organise my struct-arrays, and this is exactly what I was looking for. I'll add a new comment whenever I get time to test it a little better.


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