# Module:Example

local p = {}; --All Lua modules on Wikipedia must begin by defining a variable
--that will hold their externally accessible functions.
--Such variables can have whatever name you want and may
--also contain various data as well as functions.
p.hello = function --Add a function to "p".
--Such functions are callable in Wikipedia
--via the #invoke command.
--"" will contain the data that Wikipedia
--sends this function when it runs.
-- 'Hello' is a name of your choice. The same name needs to be referred to when the module is used.  
local str = "Hello World!" --Declare a local variable and set it equal to
--"Hello World!".  
return str --This tells us to quit this function and send the information in
--"str" back to Wikipedia.  
end -- end of the function "hello"
function p.hello_to -- Add another function
local name = .args[1] -- To access arguments passed to a module, use `.args`
-- `.args[1]` refers to the first unnamed parameter
-- given to the module
return "Hello, " .. name .. "!" -- `..` concatenates strings. This will return a customized
-- greeting depending on the name given, such as "Hello, Fred!"
end
function p.count_fruit
local num_bananas = .args.bananas -- Named arguments are likewise
local num_apples = .args.apples -- accessed by indexing `.args` by name (`.args["bananas"]`, or)
-- equivalently `.args.bananas`.
return 'I have ' .. num_bananas .. ' bananas and ' .. num_apples .. ' apples'
-- Like above, concatenate a bunch of strings together to produce
-- a sentence based on the arguments given.
end  
local function lucky(a, b) -- One can define custom functions for use. Here we define a function 'lucky' that has two inputs a and b. The names are of your choice.
if b == 'yeah' then -- Condition: if b is the string 'yeah'. Strings require quotes. Remember to include 'then'.
return a .. ' is my lucky number.' -- Outputs 'a is my lucky number.' if the above condition is met. The string concatenation operator is denoted by 2 dots.
else -- If no conditions are met, i.e. if b is anything else, output specified on the next line. 'else' should not have 'then'.
return a -- Simply output a.
end -- The 'if' section should end with 'end'.
end -- As should 'function'.  
function p.Name2
-- The next five lines are mostly for convenience only and can be used as is for your module. The output conditions start on line 50.
local pf = :getParent.args -- This line allows template parameters to be used in this code easily. The equal sign is used to define variables. 'pf' can be replaced with a word of your choice.
local f = .args -- This line allows parameters from to be used easily. 'f' can be replaced with a word of your choice.
local M = f[1] or pf[1] -- f[1] and pf[1], which we just defined, refer to the first parameter. This line shortens them as 'M' for convenience. You could use the original variable names.
local m = f[2] or pf[2] -- Second shortened as 'm'.
local l = f.lucky or pf.lucky -- A named parameter 'lucky' is shortend as l. Note that the syntax is different from unnamed parameters.
if m == nil then -- If the second parameter is not used.
return 'Lonely' -- Outputs the string 'Lonely' if the first condition is met.
elseif M > m then -- If the first condition is not met, this line tests a second condition: if M is greater than m.
return lucky(M - m, l) -- If the condition is met, the difference is calculated and passed to the self defined function along with l. The output depends on whether l is set to 'yeah'.
else
return 'Be positive!'
end
end  
return p --All modules end by returning the variable containing their functions to Wikipedia.
-- Now we can use this module by calling ,
-- , or
-- Note that the first part of the invoke is the name of the Module's wikipage,
-- and the second part is the name of one of the functions attached to the
-- variable that you returned.  
-- The "print" function is not allowed in Wikipedia. All output is accomplished
-- via strings "returned" to Wikipedia.