Default sword script "Player" variable location

[ProxyRequest (Sif)]

I’m confused where are they getting this “Player” variable from? (I’m pointing at it in green arrow)
This is the default sword script provided by “Roblox”
Note that it’s different from the lowercased “player”

Here’s the entire code:

--Rescripted by Luckymaxer
--EUROCOW WAS HERE BECAUSE I MADE THE PARTICLES AND THEREFORE THIS ENTIRE SWORD PRETTY AND LOOK PRETTY WORDS AND I'D LIKE TO DEDICATE THIS TO MY FRIENDS AND HI LUCKYMAXER PLS FIX SFOTH SWORDS TY LOVE Y'ALl
--Updated for R15 avatars by StarWars
--Re-updated by TakeoHonorable

Tool = script.Parent
Handle = Tool:WaitForChild("Handle")

function Create(ty)
	return function(data)
		local obj = Instance.new(ty)
		for k, v in pairs(data) do
			if type(k) == 'number' then
				v.Parent = obj
			else
				obj[k] = v
			end
		end
		return obj
	end
end

local BaseUrl = "rbxassetid://"

Players = game:GetService("Players")
Debris = game:GetService("Debris")
RunService = game:GetService("RunService")

DamageValues = {
	BaseDamage = 5,
	SlashDamage = 10,
	LungeDamage = 30
}

--For R15 avatars
Animations = {
	R15Slash = 522635514,
	R15Lunge = 522638767
}

Damage = DamageValues.BaseDamage

Grips = {
	Up = CFrame.new(0, 0, -1.70000005, 0, 0, 1, 1, 0, 0, 0, 1, 0),
	Out = CFrame.new(0, 0, -1.70000005, 0, 1, 0, 1, -0, 0, 0, 0, -1)
}

Sounds = {
	Slash = Handle:WaitForChild("SwordSlash"),
	Lunge = Handle:WaitForChild("SwordLunge"),
	Unsheath = Handle:WaitForChild("Unsheath")
}

ToolEquipped = false

--For Omega Rainbow Katana thumbnail to display a lot of particles.
for i, v in pairs(Handle:GetChildren()) do
	if v:IsA("ParticleEmitter") then
		v.Rate = 20
	end
end

Tool.Grip = Grips.Up
Tool.Enabled = true

function IsTeamMate(Player1, Player2)
	return (Player1 and Player2 and not Player1.Neutral and not Player2.Neutral and Player1.TeamColor == Player2.TeamColor)
end

function TagHumanoid(humanoid, player)
	local Creator_Tag = Instance.new("ObjectValue")
	Creator_Tag.Name = "creator"
	Creator_Tag.Value = player
	Debris:AddItem(Creator_Tag, 2)
	Creator_Tag.Parent = humanoid
end

function UntagHumanoid(humanoid)
	for i, v in pairs(humanoid:GetChildren()) do
		if v:IsA("ObjectValue") and v.Name == "creator" then
			v:Destroy()
		end
	end
end

function Blow(Hit)
	if not Hit or not Hit.Parent or not CheckIfAlive() or not ToolEquipped then
		return
	end
	local RightArm = Character:FindFirstChild("Right Arm") or Character:FindFirstChild("RightHand")
	if not RightArm then
		return
	end
	local RightGrip = RightArm:FindFirstChild("RightGrip")
	if not RightGrip or (RightGrip.Part0 ~= Handle and RightGrip.Part1 ~= Handle) then
		return
	end
	local character = Hit.Parent
	if character == Character then
		return
	end
	local humanoid = character:FindFirstChildOfClass("Humanoid")
	if not humanoid or humanoid.Health == 0 then
		return
	end
	local player = Players:GetPlayerFromCharacter(character)
	if player and (player == Player or IsTeamMate(Player, player)) then
		return
	end
	UntagHumanoid(humanoid)
	TagHumanoid(humanoid, Player)
	humanoid:TakeDamage(Damage)	
end


function Attack()
	Damage = DamageValues.SlashDamage
	Sounds.Slash:Play()

	if Humanoid then
		if Humanoid.RigType == Enum.HumanoidRigType.R6 then
			local Anim = Instance.new("StringValue")
			Anim.Name = "toolanim"
			Anim.Value = "Slash"
			Anim.Parent = Tool
		elseif Humanoid.RigType == Enum.HumanoidRigType.R15 then
			local Anim = Tool:FindFirstChild("R15Slash")
			if Anim then
				local Track = Humanoid:LoadAnimation(Anim)
				Track:Play(0)
			end
		end
	end	
end

function Lunge()
	Damage = DamageValues.LungeDamage

	Sounds.Lunge:Play()
	
	if Humanoid then
		if Humanoid.RigType == Enum.HumanoidRigType.R6 then
			local Anim = Instance.new("StringValue")
			Anim.Name = "toolanim"
			Anim.Value = "Lunge"
			Anim.Parent = Tool
		elseif Humanoid.RigType == Enum.HumanoidRigType.R15 then
			local Anim = Tool:FindFirstChild("R15Lunge")
			if Anim then
				local Track = Humanoid:LoadAnimation(Anim)
				Track:Play(0)
			end
		end
	end	
	--[[
	if CheckIfAlive() then
		local Force = Instance.new("BodyVelocity")
		Force.velocity = Vector3.new(0, 10, 0) 
		Force.maxForce = Vector3.new(0, 4000, 0)
		Debris:AddItem(Force, 0.4)
		Force.Parent = Torso
	end
	]]
	
	wait(0.2)
	Tool.Grip = Grips.Out
	wait(0.6)
	Tool.Grip = Grips.Up

	Damage = DamageValues.SlashDamage
end

Tool.Enabled = true
LastAttack = 0

function Activated()
	if not Tool.Enabled or not ToolEquipped or not CheckIfAlive() then
		return
	end
	Tool.Enabled = false
	local Tick = RunService.Stepped:wait()
	if (Tick - LastAttack < 0.2) then
		Lunge()
	else
		Attack()
	end
	LastAttack = Tick
	--wait(0.5)
	Damage = DamageValues.BaseDamage
	local SlashAnim = (Tool:FindFirstChild("R15Slash") or Create("Animation"){
		Name = "R15Slash",
		AnimationId = BaseUrl .. Animations.R15Slash,
		Parent = Tool
	})
	
	local LungeAnim = (Tool:FindFirstChild("R15Lunge") or Create("Animation"){
		Name = "R15Lunge",
		AnimationId = BaseUrl .. Animations.R15Lunge,
		Parent = Tool
	})
	Tool.Enabled = true
end

function CheckIfAlive()
	return (((Player and Player.Parent and Character and Character.Parent and Humanoid and Humanoid.Parent and Humanoid.Health > 0 and Torso and Torso.Parent) and true) or false)
end

function Equipped()
	Character = Tool.Parent
	Player = Players:GetPlayerFromCharacter(Character)
	Humanoid = Character:FindFirstChildOfClass("Humanoid")
	Torso = Character:FindFirstChild("Torso") or Character:FindFirstChild("HumanoidRootPart")
	if not CheckIfAlive() then
		return
	end
	ToolEquipped = true
	Sounds.Unsheath:Play()
end

function Unequipped()
	Tool.Grip = Grips.Up
	ToolEquipped = false
end

Tool.Activated:Connect(Activated)
Tool.Equipped:Connect(Equipped)
Tool.Unequipped:Connect(Unequipped)

Connection = Handle.Touched:Connect(Blow)

[lamonLikeTinyGamer (Lamon)]

Line 210, a variable not stated as local called “Player” is initialized.
Nontheless, this is a really bad practice: you shouldn’t create global variables like this.

[yo9sa (yosa)]

The point is that a global variable is used in the function. Of course, this method is not recommended, so you may not see it very often in other scripts, however, local Player was not specified in this script, which means the variable will be global.

---

Let’s create two functions that locally constrain their execution.

local function PrintVersion()
	print(_Version)
end

local function SetVersion()
	_Version = 4.1
end

SetVersion()
PrintVersion()

You may notice that in SetVersion there is a mention of _Version, although this variable is not in the general part of the script.

Call SetVersion(). Since there is no binding local, it creates the variable as a global one.

---

And what will the console give us?

---

Now let’s not call SetVersion() and see what the console gives us.

local function PrintVersion()
	print(_Version)
end

local function SetVersion()
	_Version = 4.1
end

PrintVersion()

---

Console:

---

Essentially all this is equivalent to the following:

local _Version = 4.1

local function PrintVersion()
	print(_Version)
end

PrintVersion()

---

Console:

[ProxyRequest (Sif)]

Oh I see why was that pretty confusing, but why in the second part did it print nil instead of showing an error? since “_Version” was never declared, or is it declared implicitly when invoking print but never initialized?

[yo9sa (yosa)]

Because the script in Luau works like a big dictionary. When you access a non-existent key in a dictionary it returns nil. It’s the same here.

local dict = {
	key1 = "value"
}

print(dict.key2) --> nil