33. Events and connections — Homework solutions

Roblox snippets — paste into a Script in Studio to try them. The .lua files are in exercises/33/homework/solutions/.

Problem 1 — Touched printer

Worked solution.

part.Touched:Connect(function(otherPart)
    print(otherPart.Name .. " touched it")
end)

:Connect registers the function; it runs each time something touches the Part, passing the touching Part as otherPart.

Problem 2 — Greet on join

Worked solution.

local Players = game:GetService("Players")

Players.PlayerAdded:Connect(function(player)
    print("Welcome, " .. player.Name .. "!")
end)

PlayerAdded fires once per joining player, giving you the player.

Problem 3 — Add a debounce

Worked solution.

local collected = false

part.Touched:Connect(function(otherPart)
    if collected then return end
    collected = true
    print("bang!")
end)

The early return skips every touch after the first, so bang! prints once.

Common mistakes.

• Declaring collected inside the connected function. It would reset to false on every touch and block nothing. The flag must live outside, so it persists between touches.

Challenge — Player-only touch

Worked solution.

local Players = game:GetService("Players")

part.Touched:Connect(function(otherPart)
    local character = otherPart.Parent
    local player = Players:GetPlayerFromCharacter(character)
    if player then
        print(player.Name .. " scored")
    end
end)

GetPlayerFromCharacter returns nil for anything not part of a player's character, so the if player guard ignores stray bricks and reacts only to players.

Done?

Your code can react to the world — touches, joins, and more — with debounces to keep it sane. Next, Services and the data model maps the big containers your scripts reach into: Workspace, Players, the rest.