Learn Lua & Roblox Game Dev

-- This is a comment in Lua
-- Comments are ignored by the computer

-- 1. Print something to the screen
print("Hello, Roblox!")

-- 2. Basic math
print(10 + 5)    -- Output: 15
print(20 - 8)    -- Output: 12
print(6 * 7)     -- Output: 42
print(100 / 4)  -- Output: 25

-- 3. String concatenation (joining text)
local name = "Player1"
print("Welcome, " .. name .. "!")

-- Variables store different types of data

-- 1. Strings (text)
local playerName = "Budi"
local greeting = "Hello!"

-- 2. Numbers
local score = 100
local health = 50.5

-- 3. Booleans (true or false)
local isAlive = true
local hasShield = false

-- Using variables
print("Player: " .. playerName)
print("Score: " .. score)

-- Changing a variable
score = score + 50
print("New Score: " .. score)

-- Creating a function
local function greet(name)
    print("Hello, " .. name .. "!")
end

-- Using the function
greet("Budi")    -- Output: Hello, Budi!
greet("Siti")    -- Output: Hello, Siti!

-- Function with return value
local function add(a, b)
    return a + b
end

local result = add(10, 5)
print(result)  -- Output: 15

-- Game function example
local function calculateScore(correct, wrong)
    local points = (correct * 10) - (wrong * 5)
    return points
end

local finalScore = calculateScore(8, 2)
print("Final Score: " .. finalScore)  -- Output: 70

-- Array (list of items)
local fruits = {"Apple", "Banana", "Orange"}

-- Access items (index starts at 1!)
print(fruits[1])  -- Output: Apple
print(fruits[2])  -- Output: Banana

-- Add item
table.insert(fruits, "Mango")

-- Loop through array
for i, fruit in ipairs(fruits) do
    print(i .. ". " .. fruit)
end

-- Dictionary (key-value pairs)
local player = {
    name = "Budi",
    health = 100,
    score = 0,
    level = 1
}

-- Access dictionary values
print(player.name)   -- Output: Budi
print(player.health) -- Output: 100

-- Modify values
player.score = player.score + 50

-- Get Roblox services
local Players = game:GetService("Players")
local Workspace = game:GetService("Workspace")

-- When a player joins the game
Players.PlayerAdded:Connect(function(player)
    print(player.Name .. " joined the game!")
    
    -- Give the player a sword
    local sword = Instance.new("Tool")
    sword.Name = "Magic Sword"
    sword.Parent = player.Backpack
end)

-- Create a part (block) in the game
local part = Instance.new("Part")
part.Name = "QuizBlock"
part.Position = Vector3.new(0, 10, 0)
part.BrickColor = BrickColor.new("Bright blue")
part.Parent = Workspace

-- Detect when something touches the part
part.Touched:Connect(function(hit)
    local player = Players:GetPlayerFromCharacter(hit.Parent)
    if player then
        print(player.Name .. " touched the block!")
    end
end)

-- ============================================
-- MATH QUIZ GAME FOR ROBLOX
-- ============================================

local Players = game:GetService("Players")
local ReplicatedStorage = game:GetService("ReplicatedStorage")

-- Create RemoteEvent for client-server communication
local QuizEvent = Instance.new("RemoteEvent")
QuizEvent.Name = "QuizEvent"
QuizEvent.Parent = ReplicatedStorage

-- Questions database
local Questions = {
    {
        question = "What is 12 × 8?",
        options = {"84", "96", "108", "72"},
        answer = 2  -- Index of correct answer (96)
    },
    {
        question = "What is 45 ÷ 9?",
        options = {"4", "5", "6", "7"},
        answer = 2  -- Answer: 5
    },
    {
        question = "What is 15 + 27?",
        options = {"40", "42", "44", "46"},
        answer = 2  -- Answer: 42
    },
    {
        question = "What is 100 - 37?",
        options = {"53", "63", "73", "83"},
        answer = 1  -- Answer: 63
    },
    {
        question = "What is 9 × 7?",
        options = {"54", "63", "72", "81"},
        answer = 2  -- Answer: 63
    }
}

-- Player data storage
local PlayerData = {}

-- Initialize player when they join
local function onPlayerAdded(player)
    PlayerData[player.UserId] = {
        score = 0,
        level = 1,
        questionsAnswered = 0,
        correctAnswers = 0
    }
    
    print("Welcome " .. player.Name .. "!")
    
    -- Send first question to player
    local questionIndex = math.random(1, #Questions)
    local question = Questions[questionIndex]
    QuizEvent:FireClient(player, "newQuestion", question)
end

-- Handle player answers
local function onAnswerReceived(player, questionIndex, selectedIndex)
    local data = PlayerData[player.UserId]
    local question = Questions[questionIndex]
    
    data.questionsAnswered = data.questionsAnswered + 1
    
    if selectedIndex == question.answer then
        -- Correct answer!
        data.correctAnswers = data.correctAnswers + 1
        data.score = data.score + 10
        
        -- Level up every 5 correct answers
        if data.correctAnswers % 5 == 0 then
            data.level = data.level + 1
            print(player.Name .. " reached level " .. data.level .. "!")
        end
        
        -- Notify player of success
        QuizEvent:FireClient(player, "correct", data.score, data.level)
    else
        -- Wrong answer
        QuizEvent:FireClient(player, "wrong", question.answer)
    end
    
    -- Send next question
    local nextIndex = math.random(1, #Questions)
    QuizEvent:FireClient(player, "newQuestion", Questions[nextIndex])
end

-- Connect events
Players.PlayerAdded:Connect(onPlayerAdded)
QuizEvent.OnServerEvent:Connect(onAnswerReceived)