UserId

Property of: Player

Value Type: int64

Description:

The UserId is a Player property that contains a read-only integer that uniquely and consistently identifies every user account on Roblox. Unlike the Instance/Name of a Player, which may change according the user’s present username, this value will never change for the same account.

This property is essential when saving/loading player data using GlobalDataStore|GlobalDataStores. Use a player’s UserId as the data store key so that each player has a unique key.

Code Samples

Data Store to Leaderboard

This code sample retrieves a player’s saved gold from a data store and puts the returned value onto the leaderboard. Note that this sample does not save players’ gold — it only loads it.

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local Players = game:GetService("Players")
local goldDataStore = game:GetService("DataStoreService"):GetDataStore("Gold") 

local STARTING_GOLD = 100

local function onPlayerAdded(player)
	local playerKey = "Player_" .. player.UserId

	local leaderstats = Instance.new("IntValue")
	leaderstats.Name = "leaderstats"

	local gold = Instance.new("IntValue", leaderstats)
	gold.Name = "Gold"

	local myGold
	local success, err = pcall(function()
		myGold = goldDataStore:GetAsync(playerKey) or STARTING_GOLD
	end)
	if success then
		gold.Value = myGold
	else
		-- Failed to retrieve data
	end

	leaderstats.Parent = player
end

for _, player in pairs(Players:GetPlayers()) do
	onPlayerAdded(player)
end
Players.PlayerAdded:Connect(onPlayerAdded)

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Player.UserId

The below example would print the UserId of every user who entered a game.

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game.Players.PlayerAdded:Connect(function(player)
     print(player.UserId)
end)

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Met the Creator Badge

The following code sample gives an example of a ‘met the creator’ badge system. This script will award a specified badge (BADGE_ID) to anyone who is in a server at the same time as the user associated with OWNER_ID.

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    local BadgeService = game:GetService("BadgeService")
    local Players = game:GetService("Players")
    
    -- change these
    local OWNER_ID = 212423 -- can use game.CreatorId for published places
    local BADGE_ID = 1
    
    local ownerInGame = false
    
    local function playerAdded(newPlayer)
    	if newPlayer.UserId == OWNER_ID then
    		-- if new player is the owner, set ownerInGame to true and give everyone the badge
    		ownerInGame = true
    		for _, player in pairs(Players:GetPlayers()) do
    			-- don't award the owner
    			if player ~= newPlayer then
    				BadgeService:AwardBadge(player.UserId, BADGE_ID)
    			end
    		end
    	elseif ownerInGame then 
    		-- if the owner is in the game, award the badge
    		BadgeService:AwardBadge(newPlayer.UserId, BADGE_ID)
    	end
    end
    
    local function playerRemoving(oldPlayer)
    	if oldPlayer.UserId == OWNER_ID then
    		-- set ownerInGame to false
    		ownerInGame = false 
    	end
    end
    
    -- listen for players joining and leaving
    Players.PlayerAdded:Connect(playerAdded)
    Players.PlayerRemoving:Connect(playerRemoving)
    
    -- fire playerAdded for existing players
    for _, player in pairs(Players:GetPlayers()) do
    	playerAdded(player)
    end

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Players:GetPlayerByUserId

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local player = game:GetService("Players"):GetPlayerByUserId(1)
 
if player then
    print("Player with userId 1 is in this server! His name is: " .. player.Name)
else
    print("Player with userId 1 is not in this server!")
end

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