Why can't I reset a table by doing `table = otherTable`?

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#1

My script inn work, just experiment stuff:

local AllMaps = {"map1", "map2", "map3"}
local StoredMaps = AllMaps -- and this works btw
local CurrentMap

function SelectMap()
	if #StoredMaps <= 0 then
		StoredMaps = AllMaps -- does not work
	end
	print(StoredMaps)
	
	
	local SelectedNum = math.random(1,#StoredMaps)
	CurrentMap = StoredMaps[SelectedNum]
	table.remove(StoredMaps, SelectedNum)
end

for i = 0,9 do
	SelectMap()
end

In theory it should reset when the total values in the table are 0, which it doesn’t do:

   ▼  {
    [1] = "map1",
    [2] = "map2",
    [3] = "map3"
  }
   ▼  {
    [1] = "map1",
    [2] = "map2"
  }
   ▼  {
    [1] = "map2"
  }
  {} -- returns empty table as if it skipped the "if"
  ServerScriptService.Script:12: invalid argument #2 to 'random' (interval is empty)
#2

Put a print into the if statement to confirm it runs rq

#3

A table value does not contain a table in it. It is a memory adress where the table is actually stored.

When you have Table1 with 1 Element and Table2 with 2, and you would do Table1 = Table2 - you wouldn’t change the data of the data. You are only saving a different memory adress. At this point, Table1 and Table2 have both the same memory adress which results in both tables beeing permanently equivalent.

3 Likes
#4

This official Roblox page explains it a bit more and if you read it, you will find the solution by yourself!

1 Like
#5

Pass by reference pass by value?

#6

What do you exactly mean? Please explain further.

#7

Pretty sure you’ve provided the solution but I can’t remember the name of this occurrence.
Pass by value refers to passing parameters creating a new variable whilst pass by reference creates a reference to the memory address which would change the original data recorded in said memory address when the reference is changed.

1 Like
#8

sorry i didn’t respond, also I did check if it runs and it does run the if statement

#9

Tables or similar constructs are pass by reference. Primitives are pass by value. You have to rebuild the whole table from scratch and populate the new table.

#10

Just use “table.remove(tablename,anychild)”

#11

Yeah, read what you sent about cloning the tables. {unpack(AllMaps)} seems to do the work for arrays. Thanks