WoW:API getn

Lua/Libshortcut From TableLibraryTutorial of lua-users.org.

table.getn(table)

This is used to determine the size of a table. The size of a table is discussed at the top of this page.

> = table.getn({1,2,3})         -- Lua will count the elements if no size is specified
3
> = table.getn({1,2,3; n=10})   -- note, n overrides counting the elements
10
> t = {1,2,3}
> table.setn(t, 10)              -- set our own size with setn()
> = table.getn(t)
10
> = table.getn({1,2,3,nil,5,6}) -- sequence ends at element 3 due to nil value at 4
3

Note that Lua 5.1 supports the use of the # operator. #t is syntactic sugar for table.getn(t)

 > print( #{1,2,3} )
 3

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

t = { [0]      = "zero",   --will not be counted
      [1]      = "one",    --will be counted; 1
      [2]      = "two",    --will be counted; 2
      [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

• tcount