Operators in Lua

local a = 10
local b = 3

-- Addition (+)
print(a + b)  -- 13

-- Subtraction (-)
print(a - b)  -- 7

-- Multiplication (*)
print(a * b)  -- 30

-- Division (/)
print(a / b)  -- 3.3333333333333 (always float)

-- Modulo (%) - remainder of division
print(a % b)  -- 1

-- Exponentiation (^)
print(a ^ b)  -- 1000 (10 * 10 * 10)

-- Unary minus (-)
print(-a)  -- -10

local x = 5
local y = 10

-- Equal to
print(x == y)  -- false

-- Not equal to
print(x ~= y)  -- true

-- Less than
print(x < y)   -- true

-- Less than or equal to
print(x <= y)  -- true

-- Greater than
print(x > y)   -- false

-- Greater than or equal to
print(x >= y)  -- false

print(10 == "10")  -- false (number vs string)

local a = true
local b = false

-- Logical AND
print(a and b)  -- false
print(true and true)  -- true
print(true and false) -- false

-- Logical OR
print(a or b)   -- true
print(true or false)  -- true
print(false or false) -- false

-- Logical NOT
print(not a)    -- false
print(not b)    -- true

-- AND: stops at first false
function test1()
    print("test1 called")
    return false
end
function test2()
    print("test2 called")
    return true
end
local result = test1() and test2()  -- Only test1() is called

-- OR: stops at first true
local result = test2() or test1()  -- Only test2() is called

local first = "Hello"
local last = "World"
local full = first .. " " .. last
print(full)  -- Hello World

-- Numbers are converted to strings when concatenated
local age = 25
local message = "I am " .. age .. " years old"
print(message)  -- I am 25 years old

-- Long string concatenation
local text = "Line 1\n" .. 
             "Line 2\n" .. 
             "Line 3"
print(text)

-- String length
local text = "Hello Lua"
print(#text)  -- 9

-- Table length (array-like tables)
local fruits = {"apple", "banana", "orange"}
print(#fruits)  -- 3

-- Precedence (highest to lowest):
-- 1. ^
-- 2. not # - (unary)
-- 3. * / %
-- 4. + -
-- 5. ..
-- 6. < > <= >= ~= ==
-- 7. and
-- 8. or

-- Example of precedence
local result = 2 + 3 * 4  -- 2 + (3 * 4) = 14
print(result)

-- Use parentheses to override precedence
local result2 = (2 + 3) * 4  -- (2 + 3) * 4 = 20
print(result2)

local x = 10
local y = 5

-- Basic calculations
print("Sum:", x + y)
print("Difference:", x - y)
print("Product:", x * y)
print("Quotient:", x / y)
print("Remainder:", x % y)
print("Power:", x ^ 2)

-- Comparisons
if x > y then
    print(x, "is greater than", y)
end

-- Logical operations
local is_positive = (x > 0) and (y > 0)
local is_even = (x % 2 == 0)
print("Both positive:", is_positive)
print("X is even:", is_even)

local first_name = "John"
local last_name = "Doe"
local age = 30

local full_name = first_name .. " " .. last_name
local info = "Name: " .. full_name .. ", Age: " .. age

print(full_name)  -- John Doe
print(info)       -- Name: John Doe, Age: 30