I have a map system for my game that cycles through a random map each time the round starts. I’ve tried countless different methods but I have no clue how to make the table that stores my maps (MapTable) pick a new random index from itself each time without repeating. I want the Table to cycle through all 20 maps without repeating a single one, and then restart.
Please help!
maybe try something like this you need your maintable to stay same but setup a temp table as a random map is choosen just remove it from the table when it hits 0 or is empty then reset it again to your mainmaptable
local MainMapTable = {
1,2,3
}
local TempMapTable = {}
function ResetTempMaps()
TempMapTable = {}
for i, map in ipairs(MainMapTable) do -- setup a tempmaptable to remove maps from
TempMapTable[i] = map
end
end
function GetMap() -- this gets a new map each time
if #TempMapTable <= 0 then -- this can be called somewhere before calling getmap but it will reset the tempmaps table using the mainmaptable
ResetTempMaps()
end
local MapKey = math.random(1,#TempMapTable)
local Map = TempMapTable[MapKey] -- gets a temp map
table.remove(TempMapTable, MapKey) -- remove it from temp table so its not choosen again
return Map -- return it
end
Here’s one way you could do it:
local GameMaps={}
local function GetRandomMap()
if #GameMaps<1 then GameMaps=workspace.Maps:GetChildren() end -- Point this to your maps folder, Once GameMaps is empty is will refill with all maps
local Rnd=math.random(1, #GameMaps) -- Get a random number between 1 and maps not yet chosen
local NewMap=GameMaps[Rnd] -- Select your new map
table.remove(GameMaps, Rnd) -- Remove selected map from table so it can't be selected again
return NewMap -- returns the result
end
local NextMap=GetRandomMap()
I added your code to my script, and it seems to work at first but then I get repeating maps. After the “GetMap” function runs and it returns “Map” I added this code after the “end”
local NextMap=GetMap()
print(NextMap)
local map = NextMap:Clone()
Should I put this code anywhere else?
Same with Nyonic above you, I added your code and then
local NextMap=GetMap()
print(NextMap)
local map = NextMap:Clone()
It works but it doesn’t stop repeated maps. Not sure why
Choose a random unchosen map, if all maps are chosen, refresh. This may cause a problem where if a map is the last unchosen map, it may be chosen first after the refresh, so you also check if it wasn’t previously chosen.
local maps = {} -- Insert maps
local chosenMaps = {}
local prevMaps = {}
local function RandomMap()
local remaining = #maps
-- Pick random map that is not previously chosen
local chosen = math.random(remaining)
local map = maps[chosen]
while table.find(prevMaps,map) do
chosen = math.random(remaining)
map = maps[chosen]
end
-- Mark as previously chosen
table.insert(prevMaps,1,map)
prevMaps[math.floor(#chosenMaps+remaining/2)] = nil
-- Remove in unchosen maps
table.remove(maps,chosen)
table.insert(chosenMaps,map)
if remaining == 1 then -- If all maps is chosen, refresh
maps, chosenMaps = chosenMaps, maps
end
return map
end
-- How to run
local nextMap = RandomMap()
I tested it and it doesn’t repeat unless all maps have been chosen.
the method is certainly not through the tables, but still it is short and simple 
local maps=game.ReplicatedStorage.Maps -- maps folder
locql current=nil
local map
repeat wait()
map=maps:GetChildren()[math.random(#maps:GetChildren()]
until map.Name~=current
current=map.Name
puts the map into a variable if the map is not current, otherwise iterates over the new one and puts it into a variable
Are you sure there isn’t some other code interfering with the process? I just ran the code and it worked as expected:
local GameMaps={}
local function GetRandomMap()
if #GameMaps<1 then
print("No Maps in GameMaps - Refreshing..")
GameMaps=workspace.Maps:GetChildren()
end -- Point this to your maps folder, Once GameMaps is empty is will refill with all maps
local Rnd=math.random(1, #GameMaps) -- Get a random number between 1 and maps not yet chosen
local NewMap=GameMaps[Rnd] -- Select your new map
table.remove(GameMaps, Rnd) -- Remove selected map from table so it can't be selected again
return NewMap -- returns the result
end
for i=1, 20 do
local NextMap=GetRandomMap()
print("Map Chosen: "..NextMap.Name)
task.wait()
end
Output:
10:32:50.200 No Maps in GameMaps - Refreshing.. - Server - Script:6
10:32:50.201 Map Chosen: Map_04 - Server - Script:19
10:32:50.258 Map Chosen: Map_05 - Server - Script:19
10:32:50.570 Map Chosen: Map_03 - Server - Script:19
10:32:50.576 Map Chosen: Map_02 - Server - Script:19
10:32:50.607 Map Chosen: Map_01 - Server - Script:19
10:32:50.882 No Maps in GameMaps - Refreshing.. - Server - Script:6
10:32:50.882 Map Chosen: Map_04 - Server - Script:19
10:32:51.316 Map Chosen: Map_03 - Server - Script:19
10:32:51.356 Map Chosen: Map_01 - Server - Script:19
10:32:51.382 Map Chosen: Map_05 - Server - Script:19
10:32:51.402 Map Chosen: Map_02 - Server - Script:19
10:32:51.431 No Maps in GameMaps - Refreshing.. - Server - Script:6
10:32:51.431 Map Chosen: Map_05 - Server - Script:19
10:32:51.515 Map Chosen: Map_04 - Server - Script:19
10:32:51.537 Map Chosen: Map_03 - Server - Script:19
10:32:51.551 Map Chosen: Map_02 - Server - Script:19
10:32:51.566 Map Chosen: Map_01 - Server - Script:19
10:32:51.587 No Maps in GameMaps - Refreshing.. - Server - Script:6
10:32:51.587 Map Chosen: Map_05 - Server - Script:19
10:32:51.599 Map Chosen: Map_03 - Server - Script:19
10:32:51.616 Map Chosen: Map_01 - Server - Script:19
10:32:51.633 Map Chosen: Map_02 - Server - Script:19
10:32:51.650 Map Chosen: Map_04 - Server - Script:19
For clarity, there are just 5 folders in the Maps folder in my test.
local Game = game
local ServerStorage = Game:GetService("ServerStorage")
local MapsFolder = ServerStorage.Maps --Maps folder.
local RandomObject = Random.new()
while true do --Infinite loop.
local Maps = MapsFolder:GetChildren() --Array of maps.
repeat --Repeat loop.
local Map = table.remove(Maps, RandomObject:NextInteger(1, #Maps)) --Remove map from array and use it for a round.
--Round code here.
until #Maps == 0 --End loop when no more maps available.
end
Fairly trivial pseudo-code to help steer you in the right direction.
Sorry in advance for the late reply, I haven’t been able to get to my computer until now. (Also thanks to everyone who replied, I will test each code out to see if it fixes this problem)
Ok so the code works beautifully, only 1 problem. I want only one of the maps to spawn in for a round, and then the order continue 1 by 1 as each round ends. Currently they all spawn in at once, and it makes my game kinda laggy. Any suggestions?
By repeating choosing a new index in the table until its not equal to LastChosen makes it randomized 100% of the times
local MapTables = {
[1] = Blah,
[2] = Bleh,
}
local LastChosen
function ChooseNewMap()
local Map = math.random(1,#MapTables)
repeat Map = math.random(1,#MapTables) task.wait() until Map ~= LastChosen
LastChosen = MapTables[Map]
return MapTables[Map]
end
This may look like a complicated article but it’s visualizations and math are very effecient. it will prevent stalling like a lot of recommendations here may.
We will be twisting a shuffle implementation into drawing from a deck of cards. The in-place shuffle we use is called Fisher-Yates.
Pros:
local maps = {
"Big City",
"Desert",
"Jungle",
"Soup Isle",
}
local usedIndecies = 0
local function get_random_map(): string
-- all of our cards are "used" we reset the deck
if usedIndecies >= #maps then
usedIndecies = 0
end
-- we get how many cards are marked as "Used"
local unusedEnd = #maps - usedIndecies
-- we do not draw from the end, these are "Used" cards
-- as cards are drawn we shrink how many are available
local index = math.random(1, unusedEnd)
local gotItem = maps[index]
-- swap our selected item with our "used" end of deck
maps[index], maps[unusedEnd] = maps[unusedEnd], maps[index]
-- next draw cannot select the card we just swapped
usedIndecies += 1
return gotItem
endWell, if your using my code example then you would remove the for i=1, 20 do loop, that was only added to show the function in action during many calls.
You would just use local NextMap=GetRandomMap() once before each round starts and clone/move the chosen map to the play area.
Add all your items on another table, when choosing map, remove it from the table, when the table is empty “refill” it
Thanks to everyone who replied! I’ve learned a ton from each one of you guys. Also thanks to Sunny_Bunny, the method works, I just had to rearrange my code a bid to fit it in properly. Appreciate the help guys