Lua Scripting for FiveM 2025 - Complete Programming Guide

-- Comments in Lua start with double dashes
-- This is a single line comment
 
--[[
This is a multi-line comment
Very useful for documentation
--]]
 
-- Variables (no need to declare type)
local playerName = "John Doe"           -- String
local playerMoney = 5000                -- Number
local isAdmin = true                    -- Boolean
local playerData = nil                  -- Nil (empty value)
 
-- Numbers can be integers or floats
local playerId = 1                      -- Integer
local playerHealth = 100.0              -- Float
local temperature = -5.5                -- Negative float
 
-- Strings
local message = "Hello World"
local longMessage = [[
This is a multi-line string
Very useful for HTML or SQL
]]
local formattedMessage = string.format("Player %s has $%d", playerName, playerMoney)
 
print(formattedMessage) -- Output: Player John Doe has $5000

-- Array-like table (indexed from 1, not 0!)
local weapons = {"pistol", "rifle", "shotgun"}
print(weapons[1]) -- Output: pistol (NOT weapons[0])
 
-- Object-like table (key-value pairs)
local player = {
    name = "John",
    money = 5000,
    job = "police",
    position = {x = 100.0, y = 200.0, z = 30.0}
}
 
-- Accessing table values
print(player.name)      -- Output: John
print(player["money"])  -- Output: 5000 (alternative syntax)
 
-- Adding new values
player.level = 5
player["experience"] = 1500
 
-- Nested table access
print(player.position.x) -- Output: 100.0
 
-- Table with mixed content
local mixedTable = {
    "first item",           -- Index 1
    "second item",          -- Index 2
    name = "Mixed Table",   -- Key "name"
    count = 42              -- Key "count"
}
 
print(mixedTable[1])        -- Output: first item
print(mixedTable.name)      -- Output: Mixed Table

-- Basic function declaration
function greetPlayer(playerName)
    print("Hello, " .. playerName .. "!")
    return "Welcome to the server"
end
 
-- Function with multiple parameters and return values
function calculateDistance(x1, y1, x2, y2)
    local dx = x2 - x1
    local dy = y2 - y1
    local distance = math.sqrt(dx * dx + dy * dy)
    return distance, dx, dy  -- Multiple return values
end
 
-- Using the functions
greetPlayer("Alice")
local dist, deltaX, deltaY = calculateDistance(0, 0, 3, 4)
print("Distance: " .. dist) -- Output: Distance: 5.0
 
-- Anonymous functions (very common in FiveM)
local onPlayerJoin = function(playerId, playerName)
    print(playerName .. " joined the server!")
end
 
-- Functions can be stored in tables
local playerActions = {
    heal = function(playerId)
        -- Heal player logic
        print("Healing player " .. playerId)
    end,
    
    giveWeapon = function(playerId, weapon)
        -- Give weapon logic
        print("Giving " .. weapon .. " to player " .. playerId)
    end
}
 
-- Call functions from table
playerActions.heal(1)
playerActions.giveWeapon(1, "pistol")

-- If statements
local playerMoney = 1000
local itemPrice = 500
 
if playerMoney >= itemPrice then
    print("Player can afford the item")
    playerMoney = playerMoney - itemPrice
elseif playerMoney > 0 then
    print("Player doesn't have enough money")
else
    print("Player is broke!")
end
 
-- While loops
local countdown = 5
while countdown > 0 do
    print("Countdown: " .. countdown)
    countdown = countdown - 1
end
 
-- For loops (numeric)
for i = 1, 5 do
    print("Number: " .. i)
end
 
-- For loops (with step)
for i = 10, 1, -2 do  -- Start at 10, end at 1, step by -2
    print("Countdown: " .. i) -- Output: 10, 8, 6, 4, 2
end
 
-- For loops (iterate over tables)
local players = {"Alice", "Bob", "Charlie"}
 
-- Iterate over array values
for index, name in ipairs(players) do
    print(index .. ": " .. name)
end
 
-- Iterate over all key-value pairs
local playerData = {name = "Alice", money = 1000, job = "police"}
for key, value in pairs(playerData) do
    print(key .. " = " .. tostring(value))
end

-- Basic error handling with pcall (protected call)
local success, result = pcall(function()
    -- This might fail
    local data = JSON.decode(someJsonString)
    return data.playerName
end)
 
if success then
    print("Player name: " .. result)
else
    print("Error occurred: " .. result)
end
 
-- Custom error handling
function safeDivide(a, b)
    if b == 0 then
        error("Cannot divide by zero!")
    end
    return a / b
end
 
-- Using xpcall for more detailed error info
local function errorHandler(err)
    print("Error: " .. err)
    print("Stack trace: " .. debug.traceback())
end
 
local success, result = xpcall(function()
    return safeDivide(10, 0)
end, errorHandler)

-- SERVER SCRIPT (server/main.lua)
-- Runs on the server, has access to all players
print("This runs on the SERVER")
 
-- Server can access all players
local players = GetPlayers()
for _, playerId in ipairs(players) do
    local playerName = GetPlayerName(playerId)
    print("Server sees player: " .. playerName)
end
 
-- Server events
RegisterServerEvent('myResource:serverEvent')
AddEventHandler('myResource:serverEvent', function(data)
    local source = source  -- Player who triggered the event
    print("Server received data from player " .. source .. ": " .. data)
end)
 
-- Trigger client event for specific player
TriggerClientEvent('myResource:clientEvent', playerId, "Hello from server!")
 
-- Trigger client event for all players
TriggerClientEvent('myResource:clientEvent', -1, "Hello everyone!")

-- CLIENT SCRIPT (client/main.lua)
-- Runs on each player's client, only sees local player
print("This runs on the CLIENT")
 
-- Client can only access local player
local playerId = PlayerId()
local playerPed = PlayerPedId()
local playerName = GetPlayerName(playerId)
 
print("Client script for player: " .. playerName)
 
-- Client events
RegisterNetEvent('myResource:clientEvent')
AddEventHandler('myResource:clientEvent', function(message)
    print("Client received: " .. message)
    
    -- Show notification to this player only
    SetNotificationTextEntry("STRING")
    AddTextComponentString(message)
    DrawNotification(false, false)
end)
 
-- Trigger server event
TriggerServerEvent('myResource:serverEvent', "Hello from client!")

-- Player and Ped natives
local playerId = PlayerId()                    -- Get local player ID
local playerPed = PlayerPedId()               -- Get local player's character
local playerName = GetPlayerName(playerId)     -- Get player name
 
-- Position natives
local x, y, z = table.unpack(GetEntityCoords(playerPed))
print(string.format("Player position: %.2f, %.2f, %.2f", x, y, z))
 
-- Set player position
SetEntityCoords(playerPed, 100.0, 200.0, 30.0, false, false, false, true)
 
-- Vehicle natives
local vehicle = GetVehiclePedIsIn(playerPed, false)
if vehicle ~= 0 then
    local speed = GetEntitySpeed(vehicle)
    local speedMph = speed * 2.236936  -- Convert m/s to mph
    print("Vehicle speed: " .. math.floor(speedMph) .. " mph")
    
    -- Vehicle modification
    SetVehicleColours(vehicle, 12, 12)  -- Set primary and secondary color
    SetVehicleNumberPlateText(vehicle, "QBCORE")
end
 
-- Weapon natives
GiveWeaponToPed(playerPed, GetHashKey("WEAPON_PISTOL"), 100, false, true)
SetPedCurrentWeaponVisible(playerPed, true, true, true, true)
 
-- UI natives
SetTextFont(4)
SetTextProportional(true)
SetTextScale(0.5, 0.5)
SetTextColour(255, 255, 255, 255)
SetTextEntry("STRING")
AddTextComponentString("Hello World!")
DrawText(0.1, 0.1)  -- Draw at 10% from left, 10% from top
 
-- Weather and time natives
SetWeatherTypeNowPersist("CLEAR")
NetworkOverrideClockTime(12, 0, 0)  -- Set time to 12:00:00

-- CreateThread creates a new coroutine
CreateThread(function()
    while true do
        Wait(1000)  -- Wait 1 second (1000ms)
        print("This runs every second")
    end
end)
 
-- Multiple threads can run simultaneously
CreateThread(function()
    while true do
        Wait(5000)  -- Wait 5 seconds
        print("This runs every 5 seconds")
    end
end)
 
-- Thread with exit condition
CreateThread(function()
    local count = 0
    while count < 10 do
        Wait(1000)
        count = count + 1
        print("Count: " .. count)
    end
    print("Thread finished!")
end)
 
-- IMPORTANT: Always use Wait() in loops!
-- This is WRONG and will crash the server/client:
--[[
while true do
    -- No Wait() here will freeze the game!
    DoSomething()
end
--]]
 
-- This is CORRECT:
CreateThread(function()
    while true do
        Wait(0)  -- Minimum wait, allows other threads to run
        DoSomething()
    end
end)

-- SERVER SIDE: Register and handle events
RegisterServerEvent('playerManager:updateMoney')
AddEventHandler('playerManager:updateMoney', function(amount)
    local source = source  -- Player who triggered event
    local player = QBCore.Functions.GetPlayer(source)
    
    if player then
        player.Functions.AddMoney('cash', amount)
        TriggerClientEvent('playerManager:moneyUpdated', source, player.PlayerData.money.cash)
    end
end)
 
-- SERVER SIDE: Trigger events for clients
RegisterCommand('heal', function(source, args, rawCommand)
    -- Heal specific player
    TriggerClientEvent('playerManager:healPlayer', source)
    
    -- Or heal all players
    TriggerClientEvent('playerManager:healPlayer', -1)
end, false)
 
-- CLIENT SIDE: Register and handle events
RegisterNetEvent('playerManager:moneyUpdated')
AddEventHandler('playerManager:moneyUpdated', function(newAmount)
    print("Your new money amount: $" .. newAmount)
    
    -- Update UI or show notification
    QBCore.Functions.Notify("Money updated: $" .. newAmount, "success")
end)
 
RegisterNetEvent('playerManager:healPlayer')
AddEventHandler('playerManager:healPlayer', function()
    local playerPed = PlayerPedId()
    SetEntityHealth(playerPed, GetEntityMaxHealth(playerPed))
    print("Player healed!")
end)
 
-- CLIENT SIDE: Trigger server events
RegisterCommand('requestmoney', function(source, args)
    local amount = tonumber(args[1]) or 100
    TriggerServerEvent('playerManager:updateMoney', amount)
end, false)

-- Standard QBCore initialization (CLIENT or SERVER)
local QBCore = exports['qb-core']:GetCoreObject()
 
-- Alternative method (older scripts)
local QBCore = nil
TriggerEvent('QBCore:GetObject', function(obj) QBCore = obj end)
 
-- Ensure QBCore is loaded before using
if not QBCore then
    print("Error: QBCore not found!")
    return
end

-- SERVER SIDE: Working with players
RegisterServerEvent('myScript:doSomething')
AddEventHandler('myScript:doSomething', function()
    local src = source
    local Player = QBCore.Functions.GetPlayer(src)
    
    if not Player then
        print("Player not found!")
        return
    end
    
    -- Access player data
    local playerName = Player.PlayerData.charinfo.firstname .. " " .. Player.PlayerData.charinfo.lastname
    local playerJob = Player.PlayerData.job.name
    local playerMoney = Player.PlayerData.money.cash
    
    print(string.format("Player: %s | Job: %s | Money: $%d", playerName, playerJob, playerMoney))
    
    -- Modify player data
    Player.Functions.AddMoney('cash', 1000)
    Player.Functions.SetJob('police', 2)  -- Job name, grade
    Player.Functions.AddItem('water', 5)  -- Item name, amount
    
    -- Send notification
    TriggerClientEvent('QBCore:Notify', src, 'You received $1000!', 'success')
end)
 
-- CLIENT SIDE: Get local player data
local PlayerData = QBCore.Functions.GetPlayerData()
 
print("My character: " .. PlayerData.charinfo.firstname)
print("My job: " .. PlayerData.job.label)
print("My cash: $" .. PlayerData.money.cash)
 
-- Update local player data when it changes
RegisterNetEvent('QBCore:Player:SetPlayerData')
AddEventHandler('QBCore:Player:SetPlayerData', function(val)
    PlayerData = val
    print("Player data updated!")
end)

-- SERVER SIDE: Job-specific functionality
RegisterServerEvent('police:arrestPlayer')
AddEventHandler('police:arrestPlayer', function(targetId)
    local src = source
    local Player = QBCore.Functions.GetPlayer(src)
    local TargetPlayer = QBCore.Functions.GetPlayer(targetId)
    
    if not Player or not TargetPlayer then return end
    
    -- Check if player is police
    if Player.PlayerData.job.name == 'police' and Player.PlayerData.job.onduty then
        -- Arrest logic
        TriggerClientEvent('police:arrestAnimation', targetId)
        TriggerClientEvent('QBCore:Notify', src, 'Player arrested!', 'success')
        TriggerClientEvent('QBCore:Notify', targetId, 'You have been arrested!', 'error')
    else
        TriggerClientEvent('QBCore:Notify', src, 'You are not on duty!', 'error')
    end
end)
 
-- CLIENT SIDE: Job-specific features
CreateThread(function()
    while true do
        Wait(1000)
        
        if PlayerData.job and PlayerData.job.name == 'police' and PlayerData.job.onduty then
            -- Police-only functionality
            local playerPed = PlayerPedId()
            local coords = GetEntityCoords(playerPed)
            
            -- Check for nearby criminals or create police blips
            -- This runs only for on-duty police officers
        end
    end
end)

-- SERVER SIDE: Database queries with QBCore
local QBCore = exports['qb-core']:GetCoreObject()
 
-- Simple query
RegisterServerEvent('myScript:savePlayerData')
AddEventHandler('myScript:savePlayerData', function(data)
    local src = source
    local Player = QBCore.Functions.GetPlayer(src)
    
    if not Player then return end
    
    local citizenid = Player.PlayerData.citizenid
    
    -- Insert new record
    MySQL.insert('INSERT INTO my_table (citizenid, data) VALUES (?, ?)', {
        citizenid,
        json.encode(data)
    })
    
    -- Update existing record
    MySQL.update('UPDATE my_table SET data = ? WHERE citizenid = ?', {
        json.encode(data),
        citizenid
    })
    
    -- Query with callback
    MySQL.query('SELECT * FROM my_table WHERE citizenid = ?', {citizenid}, function(result)
        if result[1] then
            local savedData = json.decode(result[1].data)
            TriggerClientEvent('myScript:dataLoaded', src, savedData)
        end
    end)
end)
 
-- Async query (modern approach)
RegisterServerEvent('myScript:getPlayerStats')
AddEventHandler('myScript:getPlayerStats', function()
    local src = source
    local Player = QBCore.Functions.GetPlayer(src)
    if not Player then return end
    
    CreateThread(function()
        local citizenid = Player.PlayerData.citizenid
        local result = MySQL.query.await('SELECT * FROM player_stats WHERE citizenid = ?', {citizenid})
        
        if result[1] then
            TriggerClientEvent('myScript:statsLoaded', src, result[1])
        else
            -- Create default stats
            MySQL.insert('INSERT INTO player_stats (citizenid, kills, deaths) VALUES (?, ?, ?)', {
                citizenid, 0, 0
            })
        end
    end)
end)

-- SERVER SIDE: Item management
RegisterServerEvent('myScript:useSpecialItem')
AddEventHandler('myScript:useSpecialItem', function(itemName)
    local src = source
    local Player = QBCore.Functions.GetPlayer(src)
    if not Player then return end
    
    -- Check if player has item
    local item = Player.Functions.GetItemByName(itemName)
    if not item then
        TriggerClientEvent('QBCore:Notify', src, 'You dont have this item', 'error')
        return
    end
    
    -- Remove item
    if Player.Functions.RemoveItem(itemName, 1) then
        -- Item removed successfully, do something
        TriggerClientEvent('QBCore:Notify', src, 'Item used!', 'success')
        
        -- Add different item
        Player.Functions.AddItem('empty_bottle', 1)
        
        -- Trigger client effect
        TriggerClientEvent('myScript:itemEffect', src)
    end
end)
 
-- Register usable item
QBCore.Functions.CreateUseableItem('my_special_item', function(source, item)
    local Player = QBCore.Functions.GetPlayer(source)
    if not Player then return end
    
    -- Custom item usage logic
    TriggerClientEvent('myScript:useItem', source, item.name)
end)

-- SERVER SIDE: Create callback
QBCore.Functions.CreateCallback('myScript:getPlayerStats', function(source, cb, playerId)
    local targetPlayer = QBCore.Functions.GetPlayer(playerId)
    if targetPlayer then
        cb(targetPlayer.PlayerData)
    else
        cb(nil)
    end
end)
 
-- CLIENT SIDE: Use callback
QBCore.Functions.TriggerCallback('myScript:getPlayerStats', function(playerData)
    if playerData then
        print("Player job: " .. playerData.job.name)
        print("Player money: " .. playerData.money.cash)
    else
        print("Player not found")
    end
end, targetPlayerId)

-- SERVER SIDE: Advanced command handling
QBCore.Commands.Add('givemoney', 'Give money to player', {
    {name = 'id', help = 'Player ID'},
    {name = 'amount', help = 'Amount of money'}
}, true, function(source, args)
    local src = source
    local targetId = tonumber(args[1])
    local amount = tonumber(args[2])
    
    if not targetId or not amount then
        TriggerClientEvent('QBCore:Notify', src, 'Invalid arguments', 'error')
        return
    end
    
    local TargetPlayer = QBCore.Functions.GetPlayer(targetId)
    if not TargetPlayer then
        TriggerClientEvent('QBCore:Notify', src, 'Player not found', 'error')
        return
    end
    
    TargetPlayer.Functions.AddMoney('cash', amount)
    TriggerClientEvent('QBCore:Notify', src, 'Money given!', 'success')
    TriggerClientEvent('QBCore:Notify', targetId, 'You received $' .. amount, 'success')
end, 'admin')  -- Admin permission required

-- Cache frequently used values
local QBCore = exports['qb-core']:GetCoreObject()
local PlayerPedId = PlayerPedId  -- Cache native functions
local GetEntityCoords = GetEntityCoords
local Wait = Wait
 
-- Efficient distance checking
local function GetDistance(coords1, coords2)
    local dx = coords1.x - coords2.x
    local dy = coords1.y - coords2.y
    local dz = coords1.z - coords2.z
    return math.sqrt(dx*dx + dy*dy + dz*dz)
end
 
-- Optimized main loop
CreateThread(function()
    local sleepTime = 1000  -- Default sleep
    
    while true do
        local playerPed = PlayerPedId()
        local playerCoords = GetEntityCoords(playerPed)
        local nearbyAction = false
        
        -- Check for nearby interactions
        for _, location in pairs(interactionLocations) do
            local distance = GetDistance(playerCoords, location.coords)
            
            if distance < 3.0 then
                nearbyAction = true
                sleepTime = 0  -- No sleep when near interaction
                
                -- Draw text or show interaction
                DrawText3D(location.coords, "[E] Interact")
                
                if IsControlJustPressed(0, 38) then -- E key
                    TriggerServerEvent('myScript:interact', location.id)
                end
                break
            end
        end
        
        -- Dynamic sleep time for performance
        if not nearbyAction then
            sleepTime = 1000  -- Sleep longer when not near anything
        end
        
        Wait(sleepTime)
    end
end)

-- Server-side validation
RegisterServerEvent('myScript:processPayment')
AddEventHandler('myScript:processPayment', function(amount, targetId)
    local src = source
    
    -- Input validation
    if type(amount) ~= 'number' or amount <= 0 then
        print(('Invalid amount from player %d: %s'):format(src, tostring(amount)))
        return
    end
    
    if type(targetId) ~= 'number' then
        print(('Invalid target ID from player %d: %s'):format(src, tostring(targetId)))
        return
    end
    
    -- Player validation
    local Player = QBCore.Functions.GetPlayer(src)
    local TargetPlayer = QBCore.Functions.GetPlayer(targetId)
    
    if not Player or not TargetPlayer then
        TriggerClientEvent('QBCore:Notify', src, 'Invalid players', 'error')
        return
    end
    
    -- Business logic with error handling
    local success, error = pcall(function()
        if Player.PlayerData.money.cash < amount then
            error('Insufficient funds')
        end
        
        Player.Functions.RemoveMoney('cash', amount)
        TargetPlayer.Functions.AddMoney('cash', amount)
        
        return true
    end)
    
    if success then
        TriggerClientEvent('QBCore:Notify', src, 'Payment sent!', 'success')
        TriggerClientEvent('QBCore:Notify', targetId, 'Payment received!', 'success')
    else
        TriggerClientEvent('QBCore:Notify', src, error, 'error')
        print(('Payment error for player %d: %s'):format(src, error))
    end
end)

-- Cross-resource communication
-- From resource A to resource B
exports['qb-phone']:SendMessage(playerId, "Someone", "Hello!")
 
-- Check if resource exists before using
if GetResourceState('qb-phone') == 'started' then
    exports['qb-phone']:SendMessage(playerId, "Someone", "Hello!")
else
    print("qb-phone resource not available")
end
 
-- Export functions from your resource
-- In your resource (server/main.lua or client/main.lua)
exports('myFunction', function(parameter1, parameter2)
    return "Result: " .. parameter1 .. " + " .. parameter2
end)
 
-- Use from another resource
local result = exports['my-resource']:myFunction("Hello", "World")

-- config.lua
Config = {}
 
Config.Locations = {
    {
        name = "Police Station",
        coords = vector3(428.23, -984.28, 29.76),
        jobs = {"police"},
        items = {"handcuffs", "radio"}
    },
    {
        name = "Hospital",
        coords = vector3(307.27, -1433.68, 29.80),
        jobs = {"ambulance"},
        items = {"medkit", "bandage"}
    }
}
 
Config.Settings = {
    enableNotifications = true,
    checkInterval = 5000,
    maxDistance = 3.0
}
 
-- Using config in main script
for _, location in pairs(Config.Locations) do
    print("Location: " .. location.name)
    
    -- Create blips, set up interactions, etc.
    CreateThread(function()
        while true do
            Wait(Config.Settings.checkInterval)
            
            local playerPed = PlayerPedId()
            local playerCoords = GetEntityCoords(playerPed)
            local distance = #(playerCoords - location.coords)
            
            if distance < Config.Settings.maxDistance then
                -- Player is near location
                if Config.Settings.enableNotifications then
                    -- Show notification
                end
            end
        end
    end)
end

-- Useful utility functions for FiveM development
 
-- Round number to decimal places
function round(num, decimals)
    local mult = 10^(decimals or 0)
    return math.floor(num * mult + 0.5) / mult
end
 
-- Format money display
function formatMoney(amount)
    local formatted = tostring(amount)
    local k
    while true do
        formatted, k = string.gsub(formatted, "^(-?%d+)(%d%d%d)", '%1,%2')
        if k == 0 then break end
    end
    return "$" .. formatted
end
 
-- Get random table element
function getRandomTableElement(tbl)
    if #tbl == 0 then return nil end
    return tbl[math.random(#tbl)]
end
 
-- Deep copy table
function deepCopy(orig)
    local copy
    if type(orig) == 'table' then
        copy = {}
        for orig_key, orig_value in next, orig, nil do
            copy[deepCopy(orig_key)] = deepCopy(orig_value)
        end
        setmetatable(copy, deepCopy(getmetatable(orig)))
    else
        copy = orig
    end
    return copy
end
 
-- Usage examples
local money = 1234567
print(formatMoney(money)) -- Output: $1,234,567
 
local weapons = {"pistol", "rifle", "shotgun"}
local randomWeapon = getRandomTableElement(weapons)
print("Random weapon: " .. randomWeapon)

-- Good: Clear variable names and structure
local QBCore = exports['qb-core']:GetCoreObject()
 
local INTERACTION_DISTANCE = 3.0
local CHECK_INTERVAL = 1000
 
local policeStations = {
    {name = "LSPD", coords = vector3(428.23, -984.28, 29.76)},
    {name = "BCSO", coords = vector3(-449.04, 6008.14, 31.72)}
}
 
local function isPlayerNearPoliceStation(playerCoords)
    for _, station in pairs(policeStations) do
        local distance = #(playerCoords - station.coords)
        if distance <= INTERACTION_DISTANCE then
            return true, station
        end
    end
    return false, nil
end
 
-- Bad: Unclear naming and magic numbers
local a = exports['qb-core']:GetCoreObject()
local b = {
    {n = "LSPD", c = {428.23, -984.28, 29.76}},
    {n = "BCSO", c = {-449.04, 6008.14, 31.72}}
}
 
local function c(d)
    for _, e in pairs(b) do
        if #(d - vector3(e.c[1], e.c[2], e.c[3])) <= 3 then
            return true
        end
    end
    return false
end

-- Cache frequently used functions
local PlayerPedId = PlayerPedId
local GetEntityCoords = GetEntityCoords
local Wait = Wait
 
-- Use local variables for better performance
CreateThread(function()
    while true do
        local playerPed = PlayerPedId()  -- Local variable
        local coords = GetEntityCoords(playerPed)
        
        -- Your logic here
        
        Wait(1000)
    end
end)
 
-- Avoid creating tables in loops
-- Bad:
CreateThread(function()
    while true do
        local data = {x = 1, y = 2, z = 3}  -- Creates new table every iteration
        DoSomething(data)
        Wait(1000)
    end
end)
 
-- Good:
local reusableData = {x = 1, y = 2, z = 3}  -- Create once outside loop
CreateThread(function()
    while true do
        DoSomething(reusableData)
        Wait(1000)
    end
end)

-- Always validate server events
RegisterServerEvent('myScript:buyItem')
AddEventHandler('myScript:buyItem', function(itemName, quantity)
    local src = source
    
    -- Validate input types
    if type(itemName) ~= 'string' or type(quantity) ~= 'number' then
        print(('Invalid input from player %d'):format(src))
        return
    end
    
    -- Validate ranges
    if quantity <= 0 or quantity > 100 then
        print(('Invalid quantity from player %d: %d'):format(src, quantity))
        return
    end
    
    -- Validate allowed items
    local allowedItems = {
        'water', 'bread', 'bandage'
    }
    
    local itemAllowed = false
    for _, allowed in pairs(allowedItems) do
        if itemName == allowed then
            itemAllowed = true
            break
        end
    end
    
    if not itemAllowed then
        print(('Invalid item from player %d: %s'):format(src, itemName))
        return
    end
    
    -- Proceed with validated data
    local Player = QBCore.Functions.GetPlayer(src)
    if Player then
        -- Business logic here
    end
end)