How can i fix this script in roblox studio? - lua

if item:IsA("BasePart") then
item.Color = Color3.new(1,0,0)
I want to make a mouse raycast to place colors on parts and it shows me this error.
Error:attempt to index nil with IsA
I tried to change the script a bit and it ended up not working anymore.

the variable "item" needs to be an Instance (example a part or object)
the error is saying "item" is not an Instance please provide more information so we can help you : )

Related

My lua code produces the error "Object tried to call nil" when trying to check if a player has a certain trait [PZ]

I'm attempting to mod a game I've been playing recently, and I've encountered an error when writing some code that adds a new mechanic. The problem itself isn't very complicated, but I can't seem to figure out what the solution is in this context. I'm pretty new to coding, especially with lua, so I apologize if the solution is really obvious. I've looked around for some answers, but again, nothing I can find seems to help me in this specific context. The game I'm trying to mod is called Project Zomboid, if that helps.
When attempting to start the game with the mod enabled, the error "Object tried to call nil in isBloodthirsty" pops up. Here's the snippet of code that's causing the error:
local function isBloodthirsty(player)
if player:getDescriptor():getTrait() ~= "bloodthirsty" then
return false else
return true
end
end
Ignoring how poorly written it is, the code was supposed to check if the player had a certain trait, and if so, then set the value isBloodthirsty to true. I think the error is caused by lua not recognizing the value "bloodthirsty", but I'm not sure what I should put instead. If anybody has an idea of what I'm doing wrong, I'd greatly appreciate some help. If it's helpful, I can post the rest of the code.
Thanks to all the great help from the stack overflow community, I managed to figure out what my problem was. The code I had written wasn't working because lua didn't recognize "bloodthirsty" as a valid trait string. My solution was to mix up the code a bit and frame the trait as a profession instead (a profession is kind of like a collection of traits within the game). The following code worked:
local function bloodthirstyStart(player)
if player:getDescriptor():getProfession() ~= "bloodthirsty" then
return
end

Roblox Studio "attempt to concatenate nil with string"

While I was inside of Roblox Studio, I was making a script like the one before you:
local amount = 123
local Module = require(game.ServerScriptService:WaitForChild("Module"))
script.Parent.ClickDetector.MouseClick:Connect(function(player)
if player.leaderstats.Currency.Value >= amount then
player.leaderstats.Currency.Value = player.leaderstats.Currency.Value - amount
local pet = Module.chooseRandomPet()
--> print(pet.Name.." selected") <--
end
end)
When I went to use it I was greeted with "attempt to concatenate nil with string" around the area with the arrows.
What would I do in order to fix this hindrance.
Module.chooseRandomPet() returns a table that has no field "Name". I'd guess that you get a simple Lua table where you expect to get a Roblox Instance. Or for some reason you managed to assign nil to that Instance's Name property.
Either way you should make find out why you don't what you expect. I found various petModule problems online. All of them had a lot of code in common that was full of mistakes.
If you cannot make sure that you don't get what you expect you should at least handle that case properly by checking if it's a nil value you're about to concatenate.

lua attempt to call field 'createUDPSocket' (a nil value)

I am writing a LUA script, when I run the program, this result as below:
socket = net.createUDPSocket()
attempt to call field 'createUDPSocket' (a nil value)
I have been searching for many website, there seems to no much details about that. Could anyone help?
That simply means that the createUDPSocket function does not exist. Without seeing your code, that is the most anyone here is going to be able to help you with.

Why using List<T> as stack returns _GrowableList

I am new to Flutter and Dart. I have implemented list as stack reference for code here. I am calculating path from one node to other in graph. Problem with code is it returns _GrowableList on which is either empty or null but my GetAnswer do returns a correct list(checked while debugging). Why it automatically converts it into growable, How can I have my normal list?
Here is snippet of code where I am passing my graph start node and end node to instance of GetAnswer and storing back result in path variable.
That's the real internal type for the list you created. However, it shouldn't really look like this in the tooltip, this is how it looks for me:
If you can provide code that reproduces showing the tooltip like that, I'd love to take a look. Please open a bug in GitHub.
(It's possible you're on v2.11 of Dart Code - if so, please update to v2.12 and this should be improved)

Cannot Access Text In A Roblox TextBox

Whenever I try to do this set of code in robloxian lua, I can't access the textbox. This code is suppost to do this, but I think that its accessing the property of the text inside the textbox instead. Here is a somewhat representative of the code that I am using. So, lets say that Bob wants to talk to John. I would write it like this.
game.StarterGui.ScreenGui.Frame.JohnsSpeech.Text = game.StarterGui.ScreenGui.Frame.JohnsUserSetText.Text
Now, JohnsUserSetText is the textbox, and JohnsSpeech is the speech. But when I try to do this, it doesn't work. It just says whatever the text is in the properties. Any help would be appreciated. Thanks! And have a great rest of your day!
Supposed to do what?
.Text is a property of a textbox or anything similar
NOTE: You are changing a starter gui, which means anyone using that current gui won't get the updated one until they die and respawn. If you want to update the one in their GUI access it through Game.Players.playernamehere.PlayerGui
StarterGui is what the game imports into a player when it reloads everything AKA: respawning or joining
if you need tips on updating each players Gui tell me and I can give some examples
Much as M. Ziegenhorn is saying, your issue is that you're referring to the StarterGui, not the PlayerGui.
The StarterGui is the container containing the default GUIs to be given out to the player upon spawn, while PlayerGui (game.Players.Ravenshield.PlayerGui, for instance) is where the GUIs are stored for each player.
The PlayerGui can only be accessed through a LocalScript.
The easiest way to access your PlayerGui is obviously to just place the LocalScript inside the ScreenGui you're using.
Otherwise, you can also access it easily by doing game.Players.LocalPlayer.PlayerGui
If I were to put my LocalScript directly in the ScreenGui we're using, it could look like this:
local TextBox = script.Parent.TextBox
local SpeechLabel = script.Parent.SpeechLabel
SpeechLabel.Text = TextBox.Text
However, you probably want to add text whenever they write it into the TextBox. Then we need to take a look at the documentation for ROBLOX, and specifically the TextBox Object.
If you scroll down to the Events, you can take a look at the TextBox.Changed event. This will fire everytime a property of the TextBox changes.
We could also use TextBox.FocusLost, which fires when the client has unfocused the TextBox. The event supplies a boolean 'enterPressed' which tells us whether or not the client pressed enter to lose focus.
local TextBox = script.Parent.TextBox
local SpeechLabel = script.Parent.SpeechLabel
TextBox.FocusLost:Connect(function(enterPressed)
if enterPressed then -- Checking if the enterPressed is true and not nil
-- The user must have pressed enter to exit the TextBox.
-- Could mean that they're done writing something.
SpeechLabel.Text = TextBox.Text
end
end)
All events have to be bound by using the :Connect method. This is what tells ROBLOX to start 'listening' to the event, to make sure the function fires every time this occurs.

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