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This is documentation for Caché & Ensemble. See the InterSystems IRIS version of this content.

For information on migrating to InterSystems IRIS, see How to Migrate to InterSystems IRIS, available on the WRC Distributions page (login required).

Lists

A little while ago you learned that all ObjectScript data are strings. A list is a special kind of string, made up of a list of items. There are several functions for working with lists, similar to string functions covered earlier.

  • $ListBuild returns a list built from items.

  • $List returns a specific item in the list.

  • $ListLength returns the number of items in the list.

  • $ListFind searches the list for an item, and returns its item number.

SAMPLES>set addr = "One Memorial Drive", city = "Cambridge"

SAMPLES>set st = "MA", zip = "02142"

SAMPLES>set mail = $listbuild(addr, city, st, zip)

SAMPLES>write $list(mail, 2)
Cambridge
SAMPLES>write $listlength(mail)
4
SAMPLES>write $listfind(mail, "MA")
3
SAMPLES>

You can't use a list function on a non-list string, or you'll get a <LIST> error. Likewise, you usually will not use string functions on a list. Note that the abbreviations for list functions are two or three letters.

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