WoW:API getn - Revision history

Move page script: Move page script moved page API getn to WoW:API getn without leaving a redirect

2023-08-15T04:46:09Z

Move page script moved page API getn to API getn without leaving a redirect

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Revision as of 04:46, 15 August 2023

Bear at 07:47, 22 May 2020

2020-05-22T07:47:16Z

← Older revision		Revision as of 07:47, 22 May 2020
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	~~{{luaapi}}~~ {{ambox		{{ambox
	\|border=red		\|border=red
	\|type='''Warning: This article discusses use of a deprecated function.'''		\|type='''Warning: This article discusses use of a deprecated function.'''
	\|style=margin-right: 10em		\|style=margin-right: 10em
	\|info=*This function should no longer be used in Lua 5.1 and may be removed in the future.		\|info=*This function should no longer be used in Lua 5.1 and may be removed in the future.
	*Use of it will result in potential future incompatibility.}}		*Use of it will result in potential future incompatibility.}}{{luaapi}}
	From [http://lua-users.org/wiki/TableLibraryTutorial TableLibraryTutorial] of lua-users.org.		From [http://lua-users.org/wiki/TableLibraryTutorial TableLibraryTutorial] of lua-users.org.

WoWWiki>Starlightblunder: {{luaapi}}

2010-03-25T22:33:43Z

← Older revision		Revision as of 22:33, 25 March 2010
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	{{:~~Lua/Libshortcut~~\|~~getn~~\|~~table~~.~~getn~~}}		{{luaapi}} {{ambox
			\|border=red
			\|type='''Warning: This article discusses use of a deprecated function.'''
			\|style=margin-right: 10em
			\|info=*This function should no longer be used in Lua 5.1 and may be removed in the future.
			*Use of it will result in potential future incompatibility.}}
	From [http://lua-users.org/wiki/TableLibraryTutorial TableLibraryTutorial] of lua-users.org.		From [http://lua-users.org/wiki/TableLibraryTutorial TableLibraryTutorial] of lua-users.org.

	table.getn(table)		table.getn(table)
			getn(table)

	~~{{ambox~~
	~~\|border=red~~
	~~\|type='''Warning: This article discusses use of a deprecated function.'''~~
	~~\|info=*This function should no longer be used in Lua 5.1 and may be removed in the future.~~
	*Use of it will result in potential future incompatibility.}}

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

	* [[tcount]]		* [[tcount]]

	~~{{LUA}}~~

Bear at 10:03, 1 October 2009

2009-10-01T10:03:13Z

← Older revision		Revision as of 10:03, 1 October 2009
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	The length of a table t is defined to be any integer index such that t[n] is not nil and t[n+1] is nil.		The length of a table t is defined to be any integer index such that t[n] is not nil and t[n+1] is nil.
	In other words, be careful with this operator if you are using tables with holes in them. If your table has all its values between [1] and [n] for some n, with no nils in that range, the # operator will return n. Otherwise its result may be unclear.		In other words, be careful with this operator if you are using tables with holes in them. If your table has all its values between [1] and [n] for some n, with no nils in that range, the # operator will return n. Otherwise its result may be unclear.

			Note:
			The reason the returned values are different is because the tables are different. For indexed tables, or tables that start with index values like 1,2,3 for keys, use tinsert and tremove to change the contents. What # returns is actually correct, setting the index value to nil does not change the size of the table for index keys, tremove would.

	== See Also ==		== See Also ==

WoWWiki>Casull at 00:18, 31 July 2008

2008-07-31T00:18:32Z

← Older revision		Revision as of 00:18, 31 July 2008
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	> print( #{1,2,3} )		> print( #{1,2,3} )
			3
			However, it does not always behave as one might expect. Consider the following sequence:
			> t = { 1, 2, 3 }
			> dump (#t)
	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[1] = nil
			> dump (#t)
			3

	t = { ~~[0] = "zero",~~ ~~--will not be counted~~		> dump (t)
	~~[1] = "one", --will be counted; 1~~		{
	[2] = ~~"two", --will be counted;~~ 2		[2] = 2
	[3] = ~~"three", --will be counted;~~ 3		[3] = 3
	~~["four"] = "four", --will not be counted; returns 3~~		} -- table: 0x807ff70
	~~[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~~.		> dump (#{ [2] = 2, [3] = 3 })
			0
			As you can see, the # operator is unpredictable in that it can return different values for tables with identical contents. The Lua 5.1 reference manual has this to say about it [http://www.lua.org/manual/5.1/]:
			The length of a table t is defined to be any integer index such that t[n] is not nil and t[n+1] is nil.
			In other words, be careful with this operator if you are using tables with holes in them. If your table has all its values between [1] and [n] for some n, with no nils in that range, the # operator will return n. Otherwise its result may be unclear.

	== See Also ==		== See Also ==

WoWWiki>Pcj at 17:14, 4 December 2007

2007-12-04T17:14:35Z

← Older revision		Revision as of 17:14, 4 December 2007
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	table.getn(table)		table.getn(table)

	{{~~band-~~red\|'''Warning:~~'''~~ This article discusses use of a deprecated function. This function should no longer be used in Lua 5.1 and may be removed in the future. Use of it will result in potential future incompatibility.}}		{{ambox
			\|border=red
			\|type='''Warning: This article discusses use of a deprecated function.'''
			\|info=*This function should no longer be used in Lua 5.1 and may be removed in the future.
			*Use of it will result in potential future incompatibility.}}

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

WoWWiki>WoWWiki-Shirik: The # operator is NOT syntactic sugar, table.getn() is deprecated and # MUST be used

2007-05-18T08:26:02Z

The # operator is NOT syntactic sugar, table.getn() is deprecated and # MUST be used

← Older revision		Revision as of 08:26, 18 May 2007
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	table.getn(table)		table.getn(table)

			{{band-red\|'''Warning:''' This article discusses use of a deprecated function. This function should no longer be used in Lua 5.1 and may be removed in the future. Use of it will result in potential future incompatibility.}}

	This is used to determine the size of a table. The size of a table is discussed at the top of this page.		This is used to determine the size of a table. The size of a table is discussed at the top of this page.
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	3		3

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

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

WoWWiki>Casull at 03:22, 27 January 2007

2007-01-27T03:22:28Z

← Older revision		Revision as of 03:22, 27 January 2007
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	3		3

	~~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 ==		== See Also ==

WoWWiki>WoWWiki-Krag at 02:01, 18 December 2006

2006-12-18T02:01:02Z

← Older revision		Revision as of 02:01, 18 December 2006
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	> print( #{1,2,3} )		> print( #{1,2,3} )
	3		3

			It seems things are not quite that simple.
			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).
			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.
			Quoting from the linked page:
			''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.''

	== See Also ==		== See Also ==

WoWWiki>Casull: Added # operator

2006-11-30T17:57:23Z

Added # operator

← Older revision		Revision as of 17:57, 30 November 2006
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	10		10
	> = table.getn({1,2,3,nil,5,6}) -- sequence ends at element 3 due to nil value at 4		> = 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		3