WoW:API sort: Difference between revisions
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{{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. | ||
table.sort(table [, | table.sort(table [, compFunc]) | ||
sort(table[, compFunc]) | |||
Sort the elements of a table in-place (i.e. alter the table). | Sort the elements of a table in-place (i.e. alter the table). | ||
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> = table.concat(t, ", ") -- only specified size is concatenated as well | > = table.concat(t, ", ") -- only specified size is concatenated as well | ||
2, 3, 5 | 2, 3, 5 | ||
;''Warning:'' Setting the range of the sort is no longer possible since table.setn is no longer supported (setting n=3 will not set the size of the table to 3) [[User:Yssaril|Yssaril]] 05:31, 23 March 2008 (UTC) | |||
A comparison function can be provided to customise the element sorting. The comparison function must return a boolean value specifying whether the first argument should be before the second argument in the sequence. The default behaviour is for the < comparison to be made. For example, the following behaves the same as no function being supplied: | A comparison function can be provided to customise the element sorting. The comparison function must return a boolean value specifying whether the first argument should be before the second argument in the sequence. The default behaviour is for the < comparison to be made. For example, the following behaves the same as no function being supplied: | ||
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---- | ---- | ||
{ | ;''Notes:'' | ||
: Sorting tables containing non-numeric keys using a custom comparison function does not work. The function will not get called, and the table will be sorted according to some kind of internal function. | |||
==Sorting by Name== | |||
There is a user-function you can write that will sort a table by name during a for function. | |||
function pairsByKeys (t, f) | |||
local a = {} | |||
for n in pairs(t) do table.insert(a, n) end | |||
table.sort(a, f) | |||
local i = 0 -- iterator variable | |||
local iter = function () -- iterator function | |||
i = i + 1 | |||
if a[i] == nil then return nil | |||
else return a[i], t[a[i]] | |||
end | |||
end | |||
return iter | |||
end | |||
This function will replace the pairs function in a for statement. Example: | |||
for title,value in pairsByKeys(randomtable) do | |||
DEFAULT_CHAT_FRAME:AddMessage(title..", "..value); | |||
end | |||
This will print all the variables in randomtable alphabetically! |
Latest revision as of 04:47, 15 August 2023
← WoW Lua
From TableLibraryTutorial of lua-users.org.
table.sort(table [, compFunc]) sort(table[, compFunc])
Sort the elements of a table in-place (i.e. alter the table).
> t = { 3,2,5,1,4 } > table.sort(t) > = table.concat(t, ", ") -- display sorted values 1, 2, 3, 4, 5
If the table has a specified size only the range specified is sorted, e.g.,
> t = { 3,2,5,1,4; n=3 } -- construct a table with user size of 3 > table.sort(t) -- sort will be limited by user size > = table.concat(t, ", ") -- only specified size is concatenated as well 2, 3, 5
- Warning: Setting the range of the sort is no longer possible since table.setn is no longer supported (setting n=3 will not set the size of the table to 3) Yssaril 05
- 31, 23 March 2008 (UTC)
A comparison function can be provided to customise the element sorting. The comparison function must return a boolean value specifying whether the first argument should be before the second argument in the sequence. The default behaviour is for the < comparison to be made. For example, the following behaves the same as no function being supplied:
> t = { 3,2,5,1,4 } > table.sort(t, function(a,b) return a<b end) > = table.concat(t, ", ") 1, 2, 3, 4, 5
We can see if we reverse the comparison the sequence order is reversed.
> table.sort(t, function(a,b) return a>b end) > = table.concat(t, ", ") 5, 4, 3, 2, 1
- Notes:
- Sorting tables containing non-numeric keys using a custom comparison function does not work. The function will not get called, and the table will be sorted according to some kind of internal function.
Sorting by Name[edit]
There is a user-function you can write that will sort a table by name during a for function.
function pairsByKeys (t, f) local a = {} for n in pairs(t) do table.insert(a, n) end table.sort(a, f) local i = 0 -- iterator variable local iter = function () -- iterator function i = i + 1 if a[i] == nil then return nil else return a[i], t[a[i]] end end return iter end
This function will replace the pairs function in a for statement. Example:
for title,value in pairsByKeys(randomtable) do DEFAULT_CHAT_FRAME:AddMessage(title..", "..value); end
This will print all the variables in randomtable alphabetically!