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|
-----------------------------------------------------------------------
-- LEARN LUA BY EXAMPLE
-- Read from top to bottom. Run the file and modify values as you go.
-----------------------------------------------------------------------
print("Hello, Lua!") -- Printing to the console
-----------------------------------------------------------------------
-- 1. VARIABLES & TYPES
-----------------------------------------------------------------------
local name = "Lua" -- string
local version = 5.1 -- number (Lua only has one numeric type)
local isFun = true -- boolean
local nothing = nil -- nil means "no value"
print(name, version, isFun, nothing)
-----------------------------------------------------------------------
-- 2. BASIC OPERATIONS
-----------------------------------------------------------------------
local a = 10
local b = 3
print("Addition:", a + b)
print("Subtraction:", a - b)
print("Multiplication:", a * b)
print("Division:", a / b)
print("Power:", a ^ b)
print("Modulo:", a % b)
-----------------------------------------------------------------------
-- 3. STRINGS
-----------------------------------------------------------------------
local first = "Hello"
local second = "World"
-- Concatenation uses ..
local message = first .. " " .. second .. "!"
print(message)
print("Length of message:", #message)
-----------------------------------------------------------------------
-- 4. CONDITIONS (if / elseif / else)
-----------------------------------------------------------------------
local health = 25
if health > 50 then
print("You are healthy")
elseif health > 0 then
print("You are injured")
else
print("You are dead")
end
-----------------------------------------------------------------------
-- 5. LOOPS
-----------------------------------------------------------------------
-- for loop
for i = 1, 5 do
print("For loop i =", i)
end
-- while loop
local counter = 1
while counter <= 3 do
print("While loop counter =", counter)
counter = counter + 1
end
-----------------------------------------------------------------------
-- 6. TABLES (VERY IMPORTANT IN LUA)
-- Tables are arrays, dictionaries, objects, and structs all in one
-----------------------------------------------------------------------
-- Array-like table
local fruits = { "apple", "banana", "cherry" }
print("First fruit:", fruits[1]) -- Lua arrays start at 1
-- Loop over array
for i, fruit in ipairs(fruits) do
print(i, fruit)
end
-- Dictionary-like table
local player = {
name = "Hunter",
level = 60,
alive = true
}
print(player.name, player.level)
-----------------------------------------------------------------------
-- 7. FUNCTIONS
-----------------------------------------------------------------------
local function add(x, y)
return x + y
end
print("Function result:", add(4, 6))
-----------------------------------------------------------------------
-- 8. FUNCTIONS AS VALUES
-----------------------------------------------------------------------
local function apply(a, b, fn)
return fn(a, b)
end
print("Apply add:", apply(2, 3, add))
-----------------------------------------------------------------------
-- 9. SIMPLE OBJECT-LIKE TABLE
-----------------------------------------------------------------------
local Enemy = {}
Enemy.__index = Enemy
function Enemy:new(name, hp)
local obj = {
name = name,
hp = hp
}
setmetatable(obj, self)
return obj
end
function Enemy:takeDamage(amount)
self.hp = self.hp - amount
print(self.name .. " takes " .. amount .. " damage. HP =", self.hp)
end
local wolf = Enemy:new("Wolf", 40)
wolf:takeDamage(15)
-----------------------------------------------------------------------
-- 10. NIL AND CHECKING VALUES
-----------------------------------------------------------------------
local value = nil
if value == nil then
print("Value is nil")
end
-----------------------------------------------------------------------
-- 11. GLOBAL VS LOCAL
-----------------------------------------------------------------------
globalVar = "I am global" -- avoid globals when possible!
local localVar = "I am local"
print(globalVar)
print(localVar)
-----------------------------------------------------------------------
-- 12. ERROR HANDLING
-----------------------------------------------------------------------
local function risky()
error("Something went wrong!")
end
local success, err = pcall(risky)
print("Success:", success)
print("Error:", err)
-----------------------------------------------------------------------
-- END
-----------------------------------------------------------------------
print("You just walked through the basics of Lua 🎉")
|
