Basic lua: Operators

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Lua operators are expressions used to perform calculations or to pass arguments between different value types.

Conditional Operators

if Query if something does or does not meet a certain condition.
else Do something else if the query condition was not met.
elseif Used to add additional if queries, if the initial query condition was not met.
end This is used to close various queries or functions; there must be the same amount of end as if; except in instances where elseif has been used.

if

if condition is true (method 1)
local a = true

if a then
  print("a = true")
end
Basic lua (conditional operators) 1.png

if condition is true (method 2)
local a = true

if a == true then
  print("a = true")
end
Basic lua (conditional operators) 2.png

if condition is false
local a = false

if a == false then
  print("a = false")
end
Basic lua (conditional operators) 3.png

else

if condition is not met, then do else
local a = false

if a then
  print("a = true")
else
  print("a = false")
end
Basic lua (conditional operators) 4.png

elseif

if condition is not met, then do elseif
local a = false

if a then
  print("a = true")
elseif a == false then
  print("a = false")
end
Basic lua (conditional operators) 5.png

Logical Operators

and Allows you to check multiple conditions in a single if query.
or Allows you to add an alternative if query into a single if query.
not Checks if condition equals false or negative.

and

if condition a is true and condition b is false then
local a = true
local b = false

if a == true and b == false then
  print("a = true", "b = false")
end
Basic lua (logical operators) 1.png

or

if condition is true or condition == true then
local a = true

if a or a == true then
 print("a = true")
end
Basic lua (logical operators) 2.png

not

if condition is not true
local a = false

if not a then
 print("a = false")
end
Basic lua (logical operators) 3.png

Comparison Operators

== Equal to.
~= Does not equal.
>= Greater than or equal to.
> Greater than.
<= Less than or equal to.
< Less than.

equal to

if a equals 1
local a = 1

if a == 1 then
 print("a = 1")
end
Basic lua (comparison operators) 1.png

does not equal

if a does not equal 2
local a = 1

if a ~= 2 then
 print("a = " .. a)
end
Basic lua (comparison operators) 2.png

greater than or equal to

if a is greater than or equal to 2
local a = 5

if a >= 2 then
 print("a = " .. a)
end
Basic lua (comparison operators) 3.png

greater than

if a is greater than 2
local a = 3

if a > 2 then
 print("a = " .. a)
end
Basic lua (comparison operators) 4.png

less than or equal to

if a less than or equal to 2
local a = 2

if a <=  2 then
 print("a = " .. a)
end
Basic lua (comparison operators) 5.png

less than

if a less than 2
local a = 0

if a <  2 then
 print("a = " .. a)
end
Basic lua (comparison operators) 6.png

Mathematical Operators

+ Add
- Subtract or invert
* Multiply
/ Divide
^ Power
% Remainder

add

1 + 2 = 3
local a = 1
local b = 2
local result = a + b

print( result )
Basic lua (mathematical operators) 1.png

subtract

3 - 2 = 1
local a = 3
local b = 2
local result = a - b

print( result )
Basic lua (mathematical operators) 2.png

inverse

inv of 3 = -3
local a = 3
local result = -a

print( "original value: " .. a, "inversed value: " .. result )
Basic lua (mathematical operators) 3.png

multiply

2 x 2 = 4
local a = 2
local result = a * a

print( result )
Basic lua (mathematical operators) 4.png

divide

10 ÷ 5 = 2
local a = 10
local b = 5
local result = a / b

print( result )
Basic lua (mathematical operators) 5.png

power

base of 2, power of 8 (2ⁿ) = 256 (2x2=4x2=8x2=16x2=32x2=64x2=128x2=256)
local a, b = 2, 8
local result = a ^ b -- generate answer

-- break down power function into string result (ignore this code)
function power(i1, i2)
 local val = "" -- clear string
 --+--
 for i = 1, i2 do -- generate the longhand math formula
  if i < i2 then val = val..i1.."*" else val = val..i1 end
 end
 return "which is the equivalent of " .. val
end

print("power value of "..a.." & "..b.." = " .. result, power(a,b))
Basic lua (mathematical operators) 6.png

remainder

remainder of 25 ÷ 4 = 1 (25 ÷ 4 = 6.25 - 6 = 0.25 * 4 = 1)
local a = 25
local b = 4
local result = a / b -- 25 ÷ 4 = 6.25
local result_decimal = math.fmod(result, 1) -- 6.25 - 6 = 0.25
local result_rounded = math.modf(result) -- 6.25 - 0.25 = 6
local remainder = a % b -- 0.25 * 4 = 1

print("result: " .. result .. ", decimal: " .. result_decimal .. ", rounded: " .. result_rounded .. ", remainder: " .. remainder)
Basic lua (mathematical operators) 7.png

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