WoW:API getn: Difference between revisions

WoW:API getn (source)

192 bytes added , 27 January 2007

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-It seems things are not quite that simple.
+getn and the # operator start at index [1] and count up, ceasing when they reach a nil value. This means that if you have a table
-See here for details: [http://lua-users.org/wiki/LuaTableSize Lua Table Size Discussion]
-Table.getn works as you'd expect if your keys are numeric (i.e. indices).
+ t = { [0]      = "zero",   --will not be counted
-if your table has keys of other type, table.getn might give you back 0 regardless of how many key-value pairs you've stored in the table.
+       [1]      = "one",    --will be counted; 1
-Quoting from the linked page:
+       [2]      = "two",    --will be counted; 2
-''If the table has an n field with a numeric value, this value is the size of the table. Otherwise, the size is the largest numerical index with a non-nil value in the table.''
+       [3]      = "three",  --will be counted; 3
+       ["four"] = "four",   --will not be counted; returns 3
+       [5]      = "five" }  --will never be reached
+running getn(t) or #t will return 3, not the expected 4. Although there are 4 indices, it will count to three, see that t[4] is a blank spot, and return with a count of three. It will never reach 5. Furthermore, keys such as t["four"] and array values less than 1 such as t[0] are not counted at all.
 == See Also ==