✓ ANSWER ACCEPTED

How to add comma's in an updating number value?

Asked Jan 17, 20154,600 views2 answers

Ok, So basically, ive created cookie clicker like game , and I want the number to look like this : (e.g)

55,555,555 not like this : 5555555, so its easier to read. Heres what I got so far:


local sv = tostring(integer.Value) -- the number of cookies (example) that have been converted

local string = sv
local newstring = '' -- I don't know what I need to put here
for i = 1,#string do
if i%4 == 0 then
newstring = (newstring..','..string[i])
else
newstring = (newstring..string[i])
end
end

PM me @ Bubbles5610 on roblox if you have any further questions or you want my testing place uncopylocked to look at the allocated variables .

Thanks :)

AnonymousJan 17, 2015Edited Jan 21, 2015

1 comment

Please put your code in a lua box so it's easier for us to read.

AnonymousJan 17, 2015#

2 answers

✓ Accepted answer

Since string.format doesn't have a format for that you will have to create your own.

function addComas(str)
    return #str % 3 == 0 and str:reverse():gsub("(%d%d%d)", "%1,"):reverse():sub(2) or str:reverse():gsub("(%d%d%d)", "%1,"):reverse()
end

print(addComas("250000000"))
print(addComas("25000000"))

250,000,00

25,000,000

Explaining the code:

We are using three functions

string.reverse(str): It reverses str, so "Hi" becomes "iH"

string.sub(str, start, [end]): Where end is optional, it returns the substring from start to end. So string.sub("Hello", 2) returns "ello"

string.gsub(str, pattern, replace, [n]): This is quite complicated, it searches str for matches using pattern and then replaces it with replace, n is optional and it's the number of maximum substitutions it is allowed to make. So string.gsub("Hello", "llo", "lp") returns "Help"

Then we put everything together:

Let's take "250000" for example, if we use string.gsub("25000", "(%d%d%d)", "%1,") it will return 250,00 because it searches the string from left to right, so we have to reverse it.

string.reverse("25000"):gsub("(%d%d%d)", "%1,") will return "000,52" so we reverse it again to revert the process. string.reverse("25000"):gsub("(%d%d%d)", "%1,") :reverse() and that's it.

There is a problem if the string length if multiple of three, like "250" because it will become ",250" so in order to fix that we just check if it's multiple of 3 and if it is we remove the first character, that's the comma.

EDIT: There was a bug in the code where "250000" would become ",250,000" that's is if the number of digits was multiple of three, so if it is then we just remove that.

AnonymousJan 17, 2015Edited Jan 17, 2015Permalink

2 comments

Please explain to him how that specifically works, in English.

AnonymousJan 17, 2015#

This really Helped :)) Thanks

AnonymousJan 19, 2015#

Explaining lombardo's code:

function addComas(str)
    return #str > 3 and str:reverse():gsub("(%d%d%d)", "%1,"):reverse() or str
end

print(addComas("25000000"))

Basically, return #str > 3 and the entire rest of line 2 actually just counts how many characters there are in a string and every 3 lines a comma is added. The and str:reverse() bit just makes it count in reverse since that's how you would know where you would put the comma in real life.

If I'm wrong, I'm sorry. ;p

I'm not a great scripter but I can read scripts and know what they do.

AnonymousJan 17, 2015Permalink

1 comment

Thanks Guys :)

AnonymousJan 19, 2015#

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