-- Different types --
local x = 10 --number
local name = "john doe" --string
local isAlive = false -- boolean
local a = nil --no value or invalid value

print(type(name))
print(type(x))
print(type(5.8))
print(type(isAlive))
print(type(A==B))
print(type(print)) 
print(type(nil))
print(type("string")) 
print(type({})) 


--[[ 隱藏文字/註解
]]

-- Operators --

-- + addition
-- - minus
-- * multiply
-- / divide
-- ^ power
-- % modulus
-- # number
-- and : Logical AND
-- or : Logical OR

print("----Numbers Operators----")
local a = 1
local b = 2
local c = a + b
print(c) -- 3
print(a + b)
print(-b) -- -2

local x =  1 * 3 * 4 -- 12
print(x)
print(1 * 3 * 4)
print((1+3) * 2)
print(10/2) -- 5
print (2^2) -- 4
print(5%2) -- 1


print("----Concatenation----")
print("It" .. " is " .. a .. ".")


print("----increment----")
local level = 1
level = level + 1
print(level) -- 2


print("----Boolean----")
VARA = 123
VARB = 456
VARC = VARA + VARB
print(VARA == VARB)

local isAlive = true
print(isAlive) 

-- Conditional Statements --

-- Comparison Operators --

-- == equality
-- ~= inequality
-- < less than
-- > greater than
-- <= less than or equal to
-- >= greater than or equal to



print("----IF----")
local age = 10
if age > 18 then
  print("over 18")
end

local isAlive = true
if isAlive then
    print("dog")
end


print("----elseif and else----")

age = 20
if age > 18 then
  print("Adult!")
elseif age == 18 then
  print("Congratulate!")
else
  print("No drink!")
end


print("----For----")

local a = 0
for i = 1,10 do
  a = a+i
end
print(a)


print("----Combining Statements----")
local x = 10
if x == 10 and x < 0 then     --> both are true
  print("dog")
elseif x == 10 or x < 0 then  --> 1 or more are true
  print("cat")
end

print("----Nested statements----")
local x = 10
local isAlive = false
if x==10 then
  if isAlive == true then
    print("True")
  else
    print("False")
  end
end

print("----Invert Value----")
local x = 100
if not (x == 10 ) then
  print("x ~= 10")
end


print("----Function----")
function test(s, e)
    local a = 0
    for i = s, e do
        a = a+i
    end
    print(a)
end
test(1,10)