Functions

If you find yourself copying and pasting the exact same code in multiple places, you are doing it wrong. Use Functions to write reusable blocks of code.

Defining a Function

A function is like a recipe. You write the recipe once, and then you can "call" it as many times as you want to bake the cake.

local function WelcomePlayer()
    print("Welcome to the game!")
end

-- To run the code, you must "call" the function:
WelcomePlayer()

Parameters & Arguments

Functions become powerful when you give them data to work with. These pieces of data are called Parameters.

When writing modern Luau, you should use Strict Typing (name: string) to tell the script exactly what kind of data the parameter should be. This gives you amazing autocomplete features in Studio.

local function DamagePlayer(playerName: string, amount: number)
    print(playerName .. " took " .. amount .. " damage!")
end

-- Calling with arguments
DamagePlayer("ekian", 25)

Return Values

Functions don't just execute code; they can also calculate a result and return it back to wherever the function was called.

local function AddNumbers(a: number, b: number): number
    return a + b
end

local result = AddNumbers(10, 5)
print(result) -- Prints 15