The Basics of Lua Programming Language

What is Lua Language

Lua is a programming language created in 1993 in Brazil by a computer graphics group at PUC-RIO University. In the last 30 years, the language has gained a series of new features, such as object-oriented programming, functional programming, data-driven programming, and data description.

The Basic syntax

Comments

  -- comment
  print("Hello!") -- comment
  --[[
  multi-line
  comment
  ]]--

Varibles

  local a = 12 -- integer
  local b = false -- boolean
  local name = "luiz" -- string

Conditional Statements

    -- Number Comparisons
    local age = 10

    if age > 18 then
       print("You age are over 18")
    end

    -- elseif and else
    age = 30

    if age > 18 then
      print("over 18")
    elseif age == 18 then
      print("18 yay!")
    else
      print("kiddo")
    end


    -- Booolean comparison
    local Live = true

    if Live then
       print("Be Alive!")
    end

    -- String comparisons
    local name = "Linus"

    if name ~= "Linus" then
       print("Not Linus")
    end

Functions

   local function print_number(num)
      print(num)
   end

   -- or

   local print_num = function(num)
      print(num)
   end

   print_num(5) -- prints 5

   -- multiple parameters
   function sum(a, b)
      return a + b
   end

Loops

Different ways to make a loop:

While

   local i = 1

   while i <= 3 do
      print("hello")
      i = i + 1
   end

For

   for i = 1, 3 do
      print("hello")
   end
   -- Both print "hello" 3 times

Tables

Tables are used to store complex data structures
Types of tables: arrays and dictionaries

Arrays

Items can be accessed by "index"


   local languages = {"lua", "c++", "python"} -- In Lua Arrays are start in 1 not in 0
   print(languages[1]) -- lua

   -- Different ways to loop through lists

   for i = 1, #languages do
      print(languages[i])
   end

   for index, value in ipairs(languages) do
      print(languages[index])
      -- or
      print(value)
   end

   -- If you dont use index or value here then you can replace it with _
   for _, value in ipairs(languages) do
      print(value)
   end

Dictionaries

Dictionaries contains keys and values:

   local data = {
      name = "Mark",
      age = 40,
      isAlive = true
   }

   print(data["name"])
   print(info.name)

   -- Loop by pairs
   for key,value in pairs(info) do
      print(key .. " " .. tostring(value))
   end

Conclusion

Lua Language is a very powerful language that provide lots of feature and better development experient