Number expected, got nil: How do I fix this?

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#1

I’m working on a game similar to Randomly Generated Droids where a random room spawns with random bots. This script is in the model of the room, meant to spawn a random bot on a part named ‘NPCSpawner’ and delete it. The NPC is meant to spawn with a modifier, so I have set the minimum requirement for the variable m to 1, but when the script runs it returns

Workspace.generatedrooms.2.spawnerscript:23: invalid argument #1 to ‘random’ (number expected, got nil)

Here’s the script:

local NPCS = game.Workspace.botfolder:GetChildren()

function SpawnRandomNPC()
for _, child in pairs(script.Parent:GetChildren()) do
if child.Name == (‘NPCSpawner’) then
local ChosenNPC = NPCS[math.random(#NPCS)]:Clone()

		ChosenNPC.Parent = child.Parent

		ChosenNPC.Torso.CFrame = child.CFrame
		
		local m = math.random(0,100)
		local g = 0
		local modifiers = game.ServerStorage.modifiers
		local parent = ChosenNPC
		local hum = parent.Zombie
		local highlight = parent.Highlight
		local name = parent.Name
		print(m)

		if m > 1 then
			local modifierchildren = tonumber(modifiers:GetChildren())
			g = math.random(modifierchildren)
			local modifier = modifiers[math.random(#modifiers)]
			print(modifier.Name)
			print(g)
			if modifier.Name == 'Slow' then
				hum.WalkSpeed = hum.WalkSpeed * 0.5
				highlight.FillColor.B = 138
				highlight.FillColor.G = 138
				highlight.FillColor.R = 138
				highlight.FillTransparency = 0.9
				highlight.OutlineColor.B = 138
				highlight.OutlineColor.G = 138
				highlight.OutlineColor.R = 138
				highlight.OutlineTransparency = 0
				parent.modifier.Value = 'slow'
				parent.Event:FireAllClients()
			end
		end

		child:Destroy()
	end
end

end

if script.Parent.Parent.Name == ‘generatedrooms’ then
SpawnRandomNPC()
end

#2

Try this:

		if m > 1 then
            print(tonumber(modifiers:GetChildren()))
			local modifierchildren = tonumber(modifiers:GetChildren())

To show what’s being referenced in the next line.
The problem isn’t really with that line, it’s with what values you are using. Go back through your code to figure out why the steps aren’t working the way you expect.

#3

You’re trying to convert a table to a number. To fix this, just do math.random(1,#modifierchildren)

1 Like
#4

I’m not that good with reading scripts so i’ll try your solution after i try DrMystery’s

#5

It returns this error: Workspace.generatedrooms.2.spawnerscript:23: attempt to get length of a nil value

#6

local modifierchildren = tonumber(modifiers:GetChildren())

In here you are trying to turn to a number something that is a table. You simply can’t do that. :GetChildren() returns a table with the children of the given Instance. Simply remove tonumber().

…

When making a post, you must pay attention to your own code to be sure your issue isn’t too simple, such as the one I’ve said above. If you’ve read about how # works and what :GetChildren() really does, this could’ve been resolved much earlier.

Also, you did not give enough information. You claim that there’s an error being thrown, but don’t easily reference what line it is being thrown for us. The code in the post isn’t correctly formated, that’s why some people in this comment section haven’t considered where the error actually comes from.

Either way, it looks like the error is coming from this line:

local modifier = modifiers[math.random(#modifiers)]

#modifiers is nil because “modifiers” is not a table, but simply the path to the Instance. Change the line local modifiers = game.ServerStorage.modifiers to local modifiers = game.ServerStorage.modifiers:GetChildren()

#7

Remove the tonumber(). Tonumber converts a string to a number if it’s possible eg “773” can be converted but “cookie” can’t. If it’s not possible to convert or wrong param supplied, Nil is returned, which is what’s causing the error

2 Likes
#8

Remove the tonumber() bit from this line.

Add # to make it access the number of children, i.e. g = math.random(#modifierchildren)

I suspect that you meant to use g in this case, so replace it with

local modifier = modifierschildren[g]
Updated Code 
local NPCS = game.Workspace.botfolder:GetChildren()

function SpawnRandomNPC()
	for _, child in pairs(script.Parent:GetChildren()) do
		if child.Name == ('NPCSpawner') then
			local ChosenNPC = NPCS[math.random(#NPCS)]:Clone()

			ChosenNPC.Parent = child.Parent

			ChosenNPC.Torso.CFrame = child.CFrame
			
			local m = math.random(0,100)
			local g = 0
			local modifiers = game.ServerStorage.modifiers
			local parent = ChosenNPC
			local hum = parent.Zombie
			local highlight = parent.Highlight
			local name = parent.Name
			print(m)

			if m > 1 then
				local modifierchildren = modifiers:GetChildren()
				g = math.random(#modifierchildren)
				local modifier = modifierschildren[g]
				print(modifier.Name)
				print(g)
				if modifier.Name == 'Slow' then
					hum.WalkSpeed = hum.WalkSpeed * 0.5
					highlight.FillColor.B = 138
					highlight.FillColor.G = 138
					highlight.FillColor.R = 138
					highlight.FillTransparency = 0.9
					highlight.OutlineColor.B = 138
					highlight.OutlineColor.G = 138
					highlight.OutlineColor.R = 138
					highlight.OutlineTransparency = 0
					parent.modifier.Value = 'slow'
					parent.Event:FireAllClients()
				end
			end

			child:Destroy()
		end
	end
end

if script.Parent.Parent.Name == 'generatedrooms' then
	SpawnRandomNPC()
end
1 Like
#9

thanks, my code works perfectly fine now

#10

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