Roblox: General Scripting Cheat Sheet

Essential Objects

Class	Description
Part	A physical brick in the world.
Model	A container for Parts.
Folder	A container for Scripts and value objects.
Script	A container for Lua source code.
LocalScript	A Script that runs its code on a client.

Basic math functions

Operation	Description
`a + b`	Adds `a` and `b`.
`a - b`	Subtract `a` and `b`.
`a * b`	Multiply `a` and `b`.
`a / b`	Divides `a` by `b`.
`a % b`	Remainder of `a` divided by `b`.
Function	Description
`math.random(n)`	Returns random number from `1` to `n` (no negatives).
`math.random(a, b)`	Returns random number from `a` to `b`.
`math.max(...)`	Returns the largest number.
`math.min(...)`	Returns the smallest number.
`math.floor(n)`	Rounds `n` down.
`math.ceil(n)`	Rounds `n` up.
`math.abs(n)`	Returns absolute value of `n`.
`math.sqrt(n)`	Returns square root of `n`.
`math.pi`	Approx equal to `3.14159`

It's important to work out problems by hand before translating their solutions into code. Algebra is necessary for success. Read about all math functions here.

String functions

Operation	Description
`a .. b`	Combine two strings.
Function	Description
`string.len(str)`	Returns length of `str`.
`string.upper(str)`	Returns `str` in upper-case.
`string.lower(str)`	Returns `str` in lower-case.
`string.reverse(str)`	Returns `str` in reverse.
`string.rep(str, n)`	Returns `str` repeated `n` times
`string.sub(str, a, b)`	Return sub-string of `str` from `a` to `b`.

A string is a collection of characters, or text. An example of a string property is the Name property. Read all string manipulation functions here.

Tables

local list = {1, 2, 3}
local firstNum = list[1]
list[2] = 4
print("There are " .. #list .. " numbers")

local total = 0
for i = 1, #list do
   total = total + list[i]
end
print("The total is " .. total)

Tables are a collection of values. They are defined using curly braces {} with values separated by commas. Access the values inside using square brackets []. Tables are sometimes called arrays. Use a for loop to work with all items in a table individually. The :GetChildren() method returns a table of children in an object.

Constants

`game`	Parent of all game services.
`workspace`	Container for all bricks and models are stored.
`script`	The currently running script.

Finding Objects

workspace.Part:Destroy()

print(script.Parent.Name)

game.ServerStorage.Tree:Clone()

Use a period to access an object's children. Use .Parent to access an object's parent. Use constants like game, workspace, and script to identify objects in the hierarchy.

Creating objects

How do I create an object?

Using Instance.new(class) and setting the parent:
object.Parent = parent

How do I access an object's properties?

Use a period (.):
print(object.Name)

How do I set an object's properties?

Use a period (.) and equals sign (=):
part.Transparency = .5

How do I destroy an object?

Using object:Destroy()

How do I copy a preexisting object?

Using object:Clone() and setting the parent:

newTree = workspace.Tree:Clone()
newTree.Parent = workspace

General Object Functions

Method name	Description
`:FindFirstChild(name)`	Return a child with `name` or `nil` if it doesn't exist.
`:WaitForChild(name)`	Pauses until a child with a name exists and returns it.
`:IsA(className)`	Return whether the object is a certain type of object.
`:Clone()`	Makes and returns a copy of an object.
`:Destroy()`	Permanently delete an object.
`:GetChildren()`	Return a list of an object's children.

These are functions (aka methods) for all classes of ROBLOX objects. Read about all methods here.

Event basics

function onTouch(part)
   print(part.Name .. " touched me!")
end
workspace.Part.Touched:connect(onTouch)

Events are specific occurrences relating to objects. When an event fires, or occurs, all connected functions are called.

Basic functions

`wait(n)`	Wait `n` seconds then continue.
`print(...)`	Display something in the Output window.

Variables

local myScore = 5
myScore = myScore + 1
print(myScore)

local myName = "Ozzy"
print("My name is " .. myName)

Variables store data of any kind - numbers, strings, tables, objects or nil (nothing). A local variable is only accessible in the block of code it is defined in.

If statements

if workspace:FindFirstChild("Tree") then
   print("There is a tree here.")
end

if coins < 5 then
   print("You need more money.")
else
   print("You have enough money!")
end

if player.Name == "Jake" then
   print("You are an awesome guy, Jake")
elseif player.Name == "Sally" then
   print("You are a sweetheart, Sally")
else
   print("You are a pretty cool person")
end

If statements will run their code if the value between if/then is true (or not nil). They can one an else block, or any number of elseif blocks.

Loops

Numeric for loop

For counting numerically.
Example: Count from 1 to 5:

for i = 1, 5 do
   print(i)
end

Generic for loop

Most often used for object children.
Example: Print all children in object:

for i, child in pairs(object:GetChildren()) do
   print(child.Name)
end

While loop

Perform code until a condition is false.
Example: Remove all children named 'Ball'

while object:FindFirstChild("Ball") do
   object.Ball:Destroy()
end

Repeat-until loop

Perform code once, then again until a condition is true.
Ex.: Copy objects until there are 5.

repeat
   newObject = object:Clone()
   newObject.Parent = workspace
   wait(1)
until #workspace:GetChildren() >= 5

Loops are used to iterate, or repeat code a number of times.

Function examples

function sayHello()
   print("Hello, world")
end
sayHello()

function addTwoNumbers(a, b)
   print("The sum is:", a + b)
end
addTwoNumbers(3, 5)

function calculateSquare(n)
   return n * n
end
local result = calculateSquare(3)

A function is a named block of code that can be run anywhere in code by calling it by name. Functions can have arguments (given values) and/or return values.

Created By

Ozzypig
ozzypig.com

Metadata

Languages: English

Published: 25th January, 2016
Last Updated: 24th January, 2017
Rated: 5 stars based on 1 ratings

Comments

Ozzypig, 07:41 25 Jan 16

First draft published, I hope to get some good feedback on my first cheat sheet!

[deleted], 00:17 28 Jan 16

Nice work, it may be basic but you did just start. I hope you continue with this!
Some things to add:
How to make color (Color3.new).
How to move things (Vector3.new or CFrame.new).
If you haven't added function(example).
Statements like elseif, then, if, and, or.
Ect.
Nice work and I hope you continue!

Ozzypig, 17:17 25 Jan 16

Making some minor fixes and changes as I receive feedback.

speelpijn 21:27 26 Jan 16

what is child?

xCodeLua 21:27 26 Jan 16

nice, clean, and basic. good job.

UndeniableLimited 21:27 26 Jan 16

This looks great for beginners, I probably won't be using this but if I was just starting to script this would be a great help!

vach 21:27 26 Jan 16

Something like this for searching instances would be really good.

kaiHirotsku 21:27 26 Jan 16

Just realized you made Fisticuffs.Anywho, I hoped for a more in depth description, such as how you can put them together.I'm an amatuer scripter, as well as a game dev, and scripting is my weak point, anywho, thank you for the cheat sheet, may success and fortune be your reward.

XxmanwolfxX 09:23 15 Feb 16

I love this, even though I have been scripting for a while I will look at this for certain pieces. Thank you so much for making this. Can you possibly add in the keydown events and mouse down events?

Nik1080 16:09 16 Sep 16

I am a beginning scripter, and this is an awesome help! Thank you!

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Roblox: General Scripting Cheat Sheet by Ozzypig