I am trying to convert a number into a suffix as well as being able to unpack a suffix.
Example : 1 * 10^6 → 1M
Example: 1B → 10^9
The only knowledge I currently know is using if and elseif statements (which would be highly inefficient and unclean) to pack it into a suffix, but I have no clue on how I would be able to unpack a suffix.
Every post is Appreciated! 
Maybe something like this?
local Suffixes = {"K", "M", "B", "T", "Q"}
local function GetSuffix(Input)
local Base, Exponent = string.match(Input, "(%d+)^(%d+)") -- get the seperate numbers
Base, Exponent = tonumber(Base), tonumber(Exponent)
if not Base or not Exponent then return end
local Index = math.floor(Number / 3) -- get the size of the number it is (hundred, thousand, million, etc.)
return (Base/10)..Suffixes[Index] -- return the result
end
print(GetSuffix("10^6")) -- 10M
My code is untested btw lol
To do it the other way, you’d simply reverse the operations. i.e. Multiply base by 10, get the exponent
Updated Post: January 2nd, 2021
@VitalWinter made a pretty good suggestion, so I’ve rewritten the code to introduce this and made some additional improvements:
local suffixes = {"K", "M", "B", "T", "Q"} -- numbers don't go higher than 'Q' in Lua.
local function toSuffixString(n)
local i = math.floor(math.log(n, 1e3))
local v = math.pow(10, i * 3)
return ("%.1f"):format(n / v):gsub("%.?0+$", "") .. (suffixes[i] or "")
end
Then, if you want to convert back:
local function fromSuffixString(s)
local n, suffix = string.match(s, "(.*)(%a)$")
if n and suffix then
local i = table.find(suffixes, suffix) or 0
return tonumber(n) * math.pow(10, i * 3)
end
return tonumber(s)
end
Personally I would do the following for converting a number to a string with a suffix.
local suffixes = {"K", "M", "B", "T", "Q", "Qu", "S", "Se", "O", "N", "D"}
local function toSuffixString(n)
for i = #suffixes, 1, -1 do
local v = math.pow(10, i * 3)
if n >= v then
return ("%.0f"):format(n / v) .. suffixes[i]
end
end
return tostring(n)
end
While to do the reverse you could do something such as
local function fromSuffixString(s)
local v, suffix = s:match("(%d+)(.*)")
for i = 1, #suffixes do
if suffixes[i] == suffix then
return tonumber(v) * math.pow(10, i * 3)
end
end
return tonumber(v)
end
Thanks for the quick replies!
Oops clicked Send by accident way too early.
I’ve tested your code to see which one would help.
@woot3 yours seems to have worked but when I tried inputting 1500000 (1.5 Million), it came out as 2 million. I don’t want to be confusing players so decimals would be fine in this case.
If you change the following line
return ("%.0f"):format(n / v) .. suffixes[i]
to the following then you’ll be able to show numbers to 1 decimal place.
return ("%.1f"):format(n / v) .. suffixes[i]
Generally I think it’s a good idea to round your numbers at some point to keep your strings short.
Also please make sure you do NOT do the converting from suffix form part (at least if you are trying to actually store or read data accurately). I am pretty sure you will not need it because of the rounding, but just as a precaution you do not want to have a constant 1.1B because you cannot round up fast enough before you leave.
Pretty sure I fixed it now, it was an issue with string.match. FYI you should learn to debug stuff like this yourself so we only have to show you what you need to do – that’s kind of what programming is about anyway (problem solving) 
Instead of iterating through suffixes, you could check if a suffix exists at this index:
math.floor(math.log(n,1000))
How would I do that for a gui? This is the code I have in my gui:
script.Parent.Text = game.Players.LocalPlayer.leaderstats.Cash.Value
while true do
wait(0.1)
script.Parent.Text = game.Players.LocalPlayer.leaderstats.Cash.Value
end
Try something like
local suffixes = {"K", "M", "B", "T", "Q", "Qu", "S", "Se", "O", "N", "D"}
local function toSuffixString(n)
for i = #suffixes, 1, -1 do
local v = math.pow(10, i * 3)
if n >= v then
return ("%.0f"):format(n / v) .. suffixes[i]
end
end
return tostring(n)
end
script.Parent.Text = toSuffixString(game.Players.LocalPlayer.leaderstats.Cash.Value)
and also don’t use
because it can be optimised more with the code below that only runs whenever a change is made to the cash value
game.Players.LocalPlayer.leaderstats.Cash.Changed:Connect(function()
script.Parent.Text = toSuffixString(game.Players.LocalPlayer.leaderstats.Cash.Value)
end)
That’s pretty sensible. There are definitely some other things which could be improved so I’ll update the code.
local suffixes = {"K", "M", "B", "T", "Q"} -- numbers don't go higher than 'Q' in Lua.
local function toSuffixString(n)
local i = math.floor(math.log(n, 1e3))
local v = math.pow(10, i * 3)
return ("%.1f"):format(n / v):gsub("%.?0+$", "") .. (suffixes[i] or "")
end
This version rounds to one decimal place and removes trailing zeros after the decimal point which should result in better looking numbers.
Here’s the updated counterpart:
local function fromSuffixString(s)
local n, suffix = string.match(s, "(.*)(%a)$")
if n and suffix then
local i = table.find(suffixes, suffix) or 0
return tonumber(n) * math.pow(10, i * 3)
end
return tonumber(s)
end
Hey, I know this is an old topic, but I’m having a small issue.
toSuffixString(1157)
would return “1.2K” instead of “1.1K”. Is there a way I can change this?
the usage of %.1f rounds the decimal automatically, in that case it went up
you can replace
("%.1f"):format(n / v)
with
("%f"):format(math.floor(n / v * 10) / 10)
this lets you do the rounding yourself, but only by rounding down