Coin Collector

Part of the Roblox Game Scripting section of Coddy's Lua journey. Lesson 15 of 24.

The treasure pad set Coins to 100. A coin should add 1, and that brings a new problem.

Touched fires once for every body part that touches, so one step onto a coin can fire it several times. Add 1 point each time and a single coin gives several points.

The fix is a debounce: a variable that remembers "this already happened" and makes the code ignore the repeats:

local used = false
button.Touched:Connect(function(hit)
	if not used then
		used = true
		print("Pressed!")
	end
end)

not used is true while used is false, so only the first touch gets past if not used. a and b is true only when both are true: if player and not used then needs a player and an unused coin.

To let it happen again later, wait and reset it: task.wait(3) then used = false. The wait pauses only this function, so other touches keep arriving and are ignored while used is true.

value += 1 is short for value = value + 1, and CanTouch = false makes a part stop firing Touched until it is set back to true.

Challenge

Medium

The leaderstats and the Touched connections are ready, but press Play and walk through a coin: Coins jumps by more than 1.

Fix it and finish the coins:

Each coin gives exactly 1 Coin per pickup (a debounce per coin).
A collected coin hides: Transparency 1 and CanTouch false.
3 seconds later it comes back (Transparency 0, CanTouch true) and can be collected again.

Try it yourself

local Players = game:GetService("Players")
local coins = workspace.Coins

Players.PlayerAdded:Connect(function(player)
	local leaderstats = Instance.new("Folder")
	leaderstats.Name = "leaderstats"
	leaderstats.Parent = player

	local coinsValue = Instance.new("IntValue")
	coinsValue.Name = "Coins"
	coinsValue.Value = 0
	coinsValue.Parent = leaderstats
end)

for _, coin in coins:GetChildren() do
	coin.Touched:Connect(function(hit)
		local player = Players:GetPlayerFromCharacter(hit.Parent)
		if player then
			player.leaderstats.Coins.Value += 1
		end
	end)
end

Test yourself

This lesson includes a short quiz. Start the lesson to answer it and track your progress.

All lessons in Roblox Game Scripting

1Scripts and Parts

Hello, Roblox Paint a Part Stretch the Bridge Build a Platform

4Game Mechanics

Speed Pad Jump Pad Click Me The Button Door Moving Platform Checkpoints Finish Line

2Loops and Functions

Row of Pillars Staircase Builder Tower Builder Coin Factory Blinking Light Vanishing Bridge

5Your First Game

Your First Obby

3Events and Players

Touch Pad Lava Floor Leaderstats Who Touched It?Coin CollectorCoin Door

Practice on your own: Online Lua compiler