BASIC languageMaps

DeleteMapElement

Map command

Syntax

Deletes the entry of a key, or the current entry when no key is given.

DeleteMapElement(<map>() [, <key>])

Parts

<map>The map, written with its empty parentheses: stock(). It must be a NewMap variable or a map field of a record.
<key>Optional. The key to delete, turned into text. Without it, the current entry is deleted.

Returns

1 when an entry was deleted, 0 when the key does not exist or there is no current entry.

Good to know

  • When the deleted entry was the current one, the entry created just before it becomes current. Deleting the first entry leaves no current entry.
  • Deleting the current entry inside FOREACH is safe: the loop goes on with the next entry.
  • A handle made with @m("key") is not cut by the deletion: IsRef() stays true, and GetRef() creates the entry again with the default value.

Example

NewMap hp.i()hp("orc") = 30hp("elf") = 10hp("imp") = 5FOREACH hp()  IF hp() < 20 THEN DeleteMapElement(hp())NEXTConsole(Str(MapSize(hp())))   ' 1Console(Str(DeleteMapElement(hp(), "orc")))   ' 1Console(Str(DeleteMapElement(hp(), "orc")))   ' 0
In the manual : Arrays, lists and maps

See also