Difference between revisions of "Ternary Operator"
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=== Description === | === Description === | ||
− | Luau introduces a form of ternary conditional using if cond then value else alternative syntax '''https://github.com/Roblox/luau/blob/master/rfcs/syntax-if-expression.md'''. | + | 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 '''''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. | ||
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=== Examples === | === Examples === | ||
− | < | + | <syntaxhighlight lang="lua"> |
local x = if FFlagFoo then A else B | local x = if FFlagFoo then A else B | ||
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newThing = if FFlagUseNewThing then t.whatever() else nil, | newThing = if FFlagUseNewThing then t.whatever() else nil, | ||
}) | }) | ||
− | </ | + | </syntaxhighlight> |
− | < | + | <syntaxhighlight lang="lua"> |
-- more trivial example | -- more trivial example | ||
local x1 = 10 | local x1 = 10 | ||
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local checkanim | local checkanim | ||
checkanim = if ent.animation.anims[ent.animation.currentanim] then ent.animation.currentanim else g_ANIM_DEFAULT | checkanim = if ent.animation.anims[ent.animation.currentanim] then ent.animation.currentanim else g_ANIM_DEFAULT | ||
− | </ | + | </syntaxhighlight> |
=== See also === | === See also === |
Latest revision as of 15:33, 13 July 2023
Supported platforms:
Available since: Gideros 2022.5
Description
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.
Examples
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
https://wiki.gideros.rocks/index.php/Examples#TERNARY_OPERATOR_.40hgy29