Recap: Defining Table Shapes

Part of the Introduction To Luau section of Coddy's Lua journey — lesson 44 of 73.

Challenge

Medium

Create a type alias named Computer with:

id of type number
brand of type string
ramInGB of type number? (optional)
boot — a method (self: Computer) -> ()

Create two computers (attach boot with the colon definition syntax):

workstation — id 1001, brand "Dell", ramInGB 16; its boot prints [brand] is booting up...
laptop — id 1002, brand "MacBook", no ramInGB; its boot prints [brand] is starting...

Create a function specs that takes a Computer and returns a string: [brand] with [ramInGB] GB of RAM when RAM is known, otherwise [brand] with unknown RAM.

Then, in order:

call workstation:boot()
call laptop:boot()
print specs(workstation)
print specs(laptop)
print the id of workstation

Try it yourself

-- Write code here
-- 1) define type Computer (optional ramInGB, boot method)
-- 2) create workstation and laptop, attach boot with colon syntax
-- 3) write specs with a nil check on ramInGB
-- 4) boot both, print both specs, print workstation.id

All lessons in Introduction To Luau

3Typed Tables: Arrays & Maps

Typed Arrays Adding and Reading Elements What is a Map Type?Declaring and Accessing Maps Iterating Tables Mixed-Shape Tables Multi-dimensional Typed Arrays table.unpack and Varargs Recap: Arrays and Maps

6Typing Table Shapes

Inline Shape Annotations Type Aliases for Shapes Optional Properties Shapes vs. Loose Tables Extending Shapes Adding Methods to Shapes Self and Colon MethodsRecap: Defining Table Shapes

9Generics: A First Look

The Problem Generics Solve A Generic Identity Function Using a Generic Function Generic Arrays Generic Type Aliases Recap: Generic Functions