Formatting numbers European vs. American

rmiller1985

Hi all,

Is there any kind of built-in function that will detect the number format of an incoming string and convert it to the appropriate locale-specific format for a number?

For example, a user might enter 1.234,56 and I'd want it converted to 1,234.56. If the user enters 1,234.56 I wouldn't want to convert it. If the user enters 1.234 I'd want it converted to 1,234 (so there'd have to be a "number of decimal places" assumed or passed in as a parameter). If the user enters 1,234 I wouldn't want to convert it.

I'm working on an international site where I need some flexibility in input rules, but I have to deal with the numbers the same way regardless of input format. And, unfortunately, I have no control over the input format: the input isn't coming from a form but from a SOAP call.

If there's no built-in function (like some sort of reverse number_format() function), I can write one. I just don't want to re-invent the wheel! I haven't found anything in the docs that addresses this, but I figure 52,285 heads are better than one. 🙂

Thanks,
Rich

NogDog

I am not aware of any built-in function. (You can use [man]number_format/man for converting internal numeric formats into the desired output formats, but that doesn't help us here.)

Question: how do you differentiate 1,234,567 between 1234567 or 1234.567? Do you always assume exactly 2 decimal places if supplied?

rmiller1985

Well, in this case we're always going to be getting data from the same source, so I think it's going to be safe to assume that we're always going to be getting numbers in the 9.999,99 format (European). If that's true, then I might just write a two line function: remove all periods, then change any commas to a period.

If it's not true, then I'll have to write a more involved function to test for various possibilities. If one already exists, so much the better, but I won't be surprised if there isn't any built-in function for this.

Thanks,
Rich

bradgrafelman

Here's what I thought of quickly:

Check if the [man]strpos[/man] of a period is less than the [man]strpos[/man] of a comma; if so, assume it's European format. If the opposite is true, assume American.
Check if the number matches the PCRE pattern:
```
/[0-9]+,[0-9]{2}/
```
If so, assume European.
Check if the number matches the PCRE pattern:
```
/[0-9]+\.[0-9]{2}/
```
If so, assume American.
If none of the above worked, assume... well, whatever you want your default to be (which continent does your site receive the most hits from? :p).