View source for Arithmetic Operators

{{ScriptTutorial|easy|scripting}}
Roblox Lua can do mathematical calculations, much like any calculator.  In Lua, there are the following arithmetic operators:

* + Addition (e.g., 2 + 3 = 5)
* - Subtraction (e.g., 5 - 2 = 3)
* * Multiplication (e.g., 5 * 2 = 10)
* / Division (e.g., 8 / 2 = 4)
* - Unary Negation (e.g., -(20) = -20)
* ^ Exponentiation (e.g., 5 ^ 5 = 3125)
*% Modulus (Percent) (Returns the remainder of a division between two numbers e.g. 11 % 3 = 2)


{{code and output
|fit=code
|code=
print(2 + 3)
print(5 - 2)
print(5 * 2)
print(8 / 2)
print(-(20))
print(23 % 4)
|output=
5
3
10
4
-20
3
}}


==Parentheses==
Parentheses can be used in Lua. If you want something calculated first, put it in parentheses.

'''Example:'''
<syntaxhighlight lang="lua">
print((10 / 20) / 5) -- is equal to .5 / 5, which is .1
print(10 / (20 / 5)) -- is equal to 10 / 4, which is 2.5
</syntaxhighlight>

Following the associative properties of multiplication and addition, it does not matter how you organize the parentheses in certain instances.

'''Example:'''
<syntaxhighlight lang="lua">
print((10 + 20) + 5) -- is equal to 30 + 5, which is 35
print(10 + (20 + 5)) -- is equal to 10 + 25, which is 35

print((10 * 20) * 5) -- is equal to 200 * 5, which is 1000
print(10 * (20 * 5)) -- is equal to 10 * 100, which is 1000
</syntaxhighlight>

==Precedence==
{{main|Precedence}}
For the mathematic operators, Lua follows the same rules as the ones usually followed in mathematics, the ones you have been taught or will be taught at school, with the modulus operator having the same priority as multiplication and division. That means mathematic operations will be executed in the order below:

#Exponentiation (^)
#Unary Negation (-)
#Multiplication, division and modulus (*, / and %)
#Addition and subtraction (+ and -)

Just like in normal math, you can use parenthesis to change the order.

Note that multiplication and division have the same precedence, as well as addition and subtraction. This means that they will occur in whatever order they appear from left-to-right after exponents, '''not''' necessarily multiplication and then division.

==See Also==
* [http://www.lua.org/pil/3.1.html Arithmetic Operators]
* [http://www.lua.org/manual/5.1/manual.html#2.5.6 Complete Precedence Table]
* [[Function_Dump/Mathematical_Functions | Math Function Dump ]]
[[Category:Scripting Tutorials]]