Ternary Operator

From GiderosMobile

Supported platforms: Platform android.pngPlatform ios.pngPlatform mac.pngPlatform pc.png
Available since: Gideros 2022.5


Luau introduces a form of ternary conditional using if cond then value else alternative syntax.

See https://github.com/Roblox/luau/blob/master/rfcs/syntax-if-expression.md.

The if-then-else expression must match if <expr> then <expr> else <expr>. The operator can also contain an arbitrary number of elseif clauses, like if <expr> then <expr> elseif <expr> then <expr> else <expr>. Unlike if statements, else is mandatory.
The result of the expression is the then-expression when condition is truthy (not nil or false) and else-expression otherwise. Only one of the two possible resulting expressions is evaluated.


local x = if FFlagFoo then A else B

MyComponent.validateProps = t.strictInterface({
	layoutOrder = t.optional(t.number),
	newThing = if FFlagUseNewThing then t.whatever() else nil,
-- more trivial example
local x1 = 10
local x2 = 100
local x = if x1>x2 then x1 else x2 -- result x = 100

-- actual project code
local checkanim
checkanim = if ent.animation.anims[ent.animation.currentanim] then ent.animation.currentanim else g_ANIM_DEFAULT

See also