Variables¶

Naming¶

Name constants using ALL_CAPS¶

local MY_CONSTANT = "constant value"
MY_GLOBAL_CONSTANT = "another constant value"

camelCase non-constant local variable names¶

local myVariable = "variable value"

PascalCase non-constant global variable names¶

MyGlobalVariable = "global variable value"

Use underscore "_" as the name of a variable that cannot be deleted but is unused.¶

local function printValues(map)
    for _, v in pairs(map) do
        print(v)
    end
end

Enums Vs Booleans¶

Enums should be used to reflect the state of something when more than two options exist. A common anti-pattern is using multiple booleans to reflect the state. This is confusing and problematic, because the code then needs to defend against impossible states, as the combination fo booleans is able to represent more states than is desired. It also makes the code more opaque and harder to reason about. What does it mean if isWalking and isRunning are both false? That we don't know? Is the state is idle? Or maybe swimming?

BAD

local isWalking = false
local isRunning = false

GOOD

local MOVEMENT = {
    UNKNOWN = 1,
    WALKING = 2,
    RUNNING = 3
}
local movementState = MOVEMENT.UNKNOWN

Representing the state in an enum this way also makes it easier to modify in the future to add more states. Such as idle, swimming, flying, falling, etc. Adding an UNKNOWN field is useful when the enum isn't exhaustive, as a catch all to represent any other state.

Location¶

Local variables within a function should be declared as close as possible to the place where they are used. This limits what the developer must keep in their head while reading the code. Local variables declared outside of a function should be declared at the top of the file, grouped together. Global variables should be declared at the top of the file grouped together. client/server global variables should only be declared within a single client/server file. This helps keep things organized instead of spreading random globals around the resource.