Lua: Vararg

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This article assumes the use of Lua 5.1. Information may not be accurate or may need revision if you are using a different version.

A vararg statement is basically a group of arguments with a variable size. Usually, a function is defined to use only a certain number of parameters, but a vararg statement allows it to take an arbitrary amount. In Lua, a vararg statement is defined with three dots (...). This vararg statement represents a table passed to the function, containing the arguments that were provided. A function can only contain one vararg statement, which should be the last parameter.

The following function takes any number of values, chooses one at random, and returns it:

function choose(...)
     local args = {...} -- brackets are optional for vararg, because it's already a table
     return args[math.random(#args)]
end

Vararg statements can even be used along with explicit parameters, like: function test(abc, xyz, ...).