How to define a Function

Simply add function at the start, then the name of the function, and parentheses. Then write the code for the function, and end the function by saying end.
Example:

function HelloWorld()
    print("Hello World")
end

How to call a Function

To call a function, simply type the function name exactly (Lua is case sensitive) and add parentheses at the end.
Example:

HelloWorld()

Parameters

With functions, you can also add parameters. To explain it simply, when you call the function you give it data, and the function uses that data.

Parameters when defining a function.

If you want to add parameters when defining a function, simply add the parameters you want in the parentheses with the name you want it to be. If you have multiple parameters, seperate them with commas. The parameters will act like variables.
Example:

function PrintParameters(food, drink)
    print(food)
    print(drink)
end

If you called the function PrintParameters with the food being pizza, and the drink being soda, then you would get an output like this:

Pizza
Soda

Parameters when calling a function

If you want to add parameters when calling a function, simply add the parameter inside of the parentheses. If you have multiple parameters, seperate them with commas.

Example:

PrintParameters("Pizza", "Soda")

Full example

function PrintMeal(food, drink, dessert)
    print(food)
    print(drink)
    print(dessert)
end

PrintMeal("Steak", "Lemonade", "Ice Cream")

Result of the above sample program is:

Steak
Lemonade
Ice Cream

Functions

Functions are like variables, but for multiple lines of code.

Functions can also be local or global, but usually you want them to be global.