How do I check if a player is in the table?

So i'm making a frame that hides the game from people unless their on the list (I know I could just do friends only but I have a lot of friends)

and so if their on the list then the gui gets hidden else make it shown

heres the script

print'Player Kicker'
admins={"ProjectRosploit","AlexTheOtaku","Lisforlucas","Ray5069"} -- admin table
game.Players.PlayerAdded:connect(function(playa)
function tableContains(t, value) -- function to check for player
    for _, v in pairs(t) do
        if v == value then 
            return true
        end
    end
    return false
if playa and TableContains(admins, player.Name) then -- statement gets an error
	-- don't know what to put here
end
end
end)

Your statement returns an error because player in player.Name is not defined. You probably meant playa.Name.

Also, format your code in an organized manner!

print'Player Kicker'
admins = {"ProjectRosploit","AlexTheOtaku","Lisforlucas","Ray5069"} 

game.Players.PlayerAdded:connect(function(playa)
	function tableContains(t, value)
		for _, v in pairs(t) do
			if v == value then 
				return true
			end
		end
		return false
		if playa and TableContains(admins, playa.Name) then

		end
	end
end)

The issue seems to be located in the function itself.

• The function is not called outside of its scope.

• The "if" is in the wrong place.

Let's make the function a static one.

print'Player Kicker'
admins = {"ProjectRosploit","AlexTheOtaku","Lisforlucas","Ray5069"}

function tableContains(t, value)
	for _, v in pairs(t) do
		if v == value then 
			return true
		end
	end
	return false
end

game.Players.PlayerAdded:connect(function(playa)
	if playa and TableContains(admins, playa.Name) then
		
	end
end)

Now we're getting somewhere!

Now, for your GUI, I assume it's already in game.StarterGui. So, let's define it.

print'Player Kicker'
admins = {"ProjectRosploit","AlexTheOtaku","Lisforlucas","Ray5069"}

function tableContains(t, value)
	for _, v in pairs(t) do
		if v == value then 
			return true
		end
	end
	return false
end

game.Players.PlayerAdded:connect(function(playa)
	if playa then
		local PlayerGui = playa:WaitForChild("PlayerGui")
		local Gui = PlayerGui:WaitForChild("ScreenGui") -- Or however you want to name it.
		local Frame = Gui:WaitForChild("Frame")
		if TableContains(admins, playa.Name) then
			Frame.Visible = false
		else
			Frame.Visible = true
		end
	end
end)

Since game.StarterGui replicates its children to the Player's PlayerGui, the GUIs will be visible to the people in the list. So let's wrap the "if" statement with a .CharacterAdded event.

print'Player Kicker'
admins = {"ProjectRosploit","AlexTheOtaku","Lisforlucas","Ray5069"}

function tableContains(t, value)
	for _, v in pairs(t) do
		if v == value then 
			return true
		end
	end
	return false
end

game.Players.PlayerAdded:connect(function(playa)
	playa.CharacterAdded:connect(function(Character)
	-- In this case, you don't need to see if the "playa" exists.
		local PlayerGui = playa:WaitForChild("PlayerGui")
		local Gui = PlayerGui:WaitForChild("ScreenGui") -- Or however you want to name it.
		local Frame = Gui:WaitForChild("Frame")
		if TableContains(admins, playa.Name) then
			Frame.Visible = false
		else
			Frame.Visible = true
		end
	end)
end)

If you want it so that if you want to "Ban" or kick people out of your game so people don't join, use a table, and use the Kick method.

#Kick It kicks the player, if you add a string in between the "()"s then you can add a custom message

game:GetService("Players").Player1:Kick("You have been kicked from the server!")

#Final Product

local message = "You are not allowed in this game." --Add a message here
allowed = {"ProjectRosploit","AlexTheOtaku","Lisforlucas","Ray5069"}

game:GetService("Players").PlayerAdded:connect(function(plyr)
	local IsAllowed = false
	for _,allow in pairs(allowed) do
		if plyr.Name == allow then
			IsAllowed = true
		end
	end
	if not IsAllowed then
		plyr:Kick(message)
	end
end)

Hope it helps!