Question

I need a regex to get numeric values that can be

111.111,11

111,111.11

111,111

And separate the integer and decimal portions so I can store in a DB with the correct syntax

I tried ([0-9]{1,3}[,.]?)+([,.][0-9]{2})? With no success since it doesn’t detect the second part 🙁

The result should look like:

111.111,11 -> $1 = 111111; $2 = 11

Answer 1

First Answer:

This matches #,###,##0.00:

^[+-]?[0-9]{1,3}(?:\,?[0-9]{3})*(?:\.[0-9]{2})?$

And this matches #.###.##0,00:

^[+-]?[0-9]{1,3}(?:\.?[0-9]{3})*(?:\,[0-9]{2})?$

Joining the two (there are smarter/shorter ways to write it, but it works):

(?:^[+-]?[0-9]{1,3}(?:\,?[0-9]{3})*(?:\.[0-9]{2})?$)
|(?:^[+-]?[0-9]{1,3}(?:\.?[0-9]{3})*(?:\,[0-9]{2})?$)

You can also, add a capturing group to the last comma (or dot) to check which one was used.

---

Second Answer:

As pointed by Alan M, my previous solution could fail to reject a value like 11,111111.00 where a comma is missing, but the other isn’t. After some tests I reached the following regex that avoids this problem:

^[+-]?[0-9]{1,3}
(?:(?<comma>\,?)[0-9]{3})?
(?:\k<comma>[0-9]{3})*
(?:\.[0-9]{2})?$

This deserves some explanation:

• ^[+-]?[0-9]{1,3} matches the first (1 to 3) digits;

• (?:(?<comma>\,?)[0-9]{3})? matches on optional comma followed by more 3 digits, and captures the comma (or the inexistence of one) in a group called ‘comma’;

• (?:\k<comma>[0-9]{3})* matches zero-to-any repetitions of the comma used before (if any) followed by 3 digits;

• (?:\.[0-9]{2})?$ matches optional “cents” at the end of the string.

Of course, that will only cover #,###,##0.00 (not #.###.##0,00), but you can always join the regexes like I did above.

---

Final Answer:

Now, a complete solution. Indentations and line breaks are there for readability only.

^[+-]?[0-9]{1,3}
(?:
    (?:\,[0-9]{3})*
    (?:.[0-9]{2})?
|
    (?:\.[0-9]{3})*
    (?:\,[0-9]{2})?
|
    [0-9]*
    (?:[\.\,][0-9]{2})?
)$

And this variation captures the separators used:

^[+-]?[0-9]{1,3}
(?:
    (?:(?<thousand>\,)[0-9]{3})*
    (?:(?<decimal>\.)[0-9]{2})?
|
    (?:(?<thousand>\.)[0-9]{3})*
    (?:(?<decimal>\,)[0-9]{2})?
|
    [0-9]*
    (?:(?<decimal>[\.\,])[0-9]{2})?
)$

---

edit 1: “cents” are now optional;
edit 2: text added;
edit 3: second solution added;
edit 4: complete solution added;
edit 5: headings added;
edit 6: capturing added;
edit 7: last answer broke in two versions;