Tips on roblox math for beginners

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#1

Hello developpers!

While learning scripting math was a bit of confusion for me but I got the hang of it.
Now I hope I don’t make any mistakes writing this, if so correct me.
So in this topic, I’ll be simplifying basic math.

Operators

In lua to do math we use Operators.
Operators are also used for conditionnal statements like if ... else if.
These are the basic operators:

[+] Addition
[-] Substraction
[*] Multiplication
[/] Division

Changing a value

In lua we have different types of values. Now let’s focus on NumberValues.
Now for this let’s make a simple value, no need to add in anything.
So let’s add a script (doesn’t matter much where it is placed at)
So:

 OurValue = 0
 --OurValue is currently at a value of 0.
 print(OurValue)

The Output will print zero.
If you want it to print it something like “the value is x” then just do this:

print("The value is "..OurValue)

Now the Output will print “The value is 0”.
Great!
Now let’s change the value. Without any Operators
So:

  OurValue = 0
     --OurValue is currently at a value of 0.
     print(OurValue)
OurValue = 5
print(OurValue)

Now OurValue is 5. But how do you change for a value outside of a script?
Let’s add a NumberValue inside of our script! Just to change it is really simple but you need to add something at the end.
So:

local Number = script.NumberValue
print(Number.Value)
--It currently has a value of 0.
Number.Value = 5
print(Number.Value)
 --Now the value is 5!

It’s pretty basic. You just need to add .Value

Changing a value with operators

This is where the fun part begins!

Now we know how to change a value. But how do we change it with Operators?
Well it seems pretty weird at first sight but you’ll get the hang of it!

So Let’s be with our NumberValue again! Now let’s do some basic math. Let’s do a simple addition of 1 + 1.
So. let’s make the value 1:

 local Number = script.NumberValue
    print(Number.Value)
    --It currently has a value of 0.
 Number.Value = 1
    print(Number.Value)
     --Now the value is 1!

Now that it is one, time to do the simple math of 1 + 1.
Remember our operators!

Number.Value +  1
print(Number.Value)

Wait! There’s a problem. No number is printed! How is that. Well the script reader/OutPut was confused by what we were doing.
Now if it was a person and it read the script and said it out loud it would probably say:

“Ok so Number.Value is our value, good. + 1, ???. What?”

Well our script reader was confused because when we said Number.Value it thought

[Result] = + 1

You get what I’m starting to say here?
So our script reader should be reading
[Result] = [Number.Value] + 1
So let’s fix our script!

Number.Value = Number.Value + 1
print(Number.Value)
   --It will now print 2. Because 1 + 1 = 2

Now the script reader isn’t confused anymore!

And Voilà!
So that was it!
Hope you find this tutorial helpful. It is my first one.
So thanks for reading! And now, use that knowledge!

Sources:
math (roblox.com)
Operators (roblox.com)

5 Likes
#2

Don’t forget that you can do +=, -=, etc. In some cases this may be far more efficient because without it, you might have to do something along the lines of this:

myNumberWithAReallyLongNameForDemonstrationPurposes = myNumberWithAReallyLongNameForDemonstrationPurposes + 1

using the operators I just pointed out, you can just do:

myNumberWithAReallyLongNameForDemonstrationPurposes += 1

Other than that, nice tutorial!

5 Likes
#3

Woah, I didnt know this. Can you explain how += works? I cant find the meaning behind using +=

#4

Basically, saying += means:
YourNumber is equal to itself + whatever number comes after.
If you say YourNumber += 1 and YourNumber = 1 that would be saying
“Well, YourNumber = 1, and I want to change the value YourNumber by a specified number (which is 1), so set the value YourNumber to equal itself + 1”

so if I set my value to 0:

local counter = 0

and I want to change the number relative to itself (Without actually saying the variable twice), you can just tell it that Variable = Same Variable + 1

local counter = 0
counter += 1 -- add 1 to counter

print(counter) -- will print 1.

Same thing goes for -=, just you subtract instead of add.
Hope this helped, sorry if its confusing!

2 Likes
#5

Thanks you soo much! I saw the same application in a lot of scripts and was confused on what it was. You made it so clear :slightly_smiling_face:

3 Likes
#6

If it wasn’t obvious enough, you can also do multiplication and division.

local IAmGettingCloned = 2
local IAmGettingCutInHalf = 4
IAmGettingCloned *= 2 --Multiply by 2
IAmGettingCutInHalf /= 2 --Divide by 2

print(IAmGettingCloned) -- 4
print(IAmGettingCutInHalf) -- 2

Pretty neat stuff.

2 Likes
#7

it’s also possible to use “%” to get the remainder of a division problem

    local math = 3%2

if you were to print math then 1 should be outputted

2 Likes
#8

Oo that was new to me. Thanks!

#9

Now we understand more why we learn in school “x,a,b,y etc.”
That makes sense