Convert any currency string to double

Question

I need to store multiple currencies in SQL server. I understand that SQL won't support all different types of currencies (unless I store it as a string, but I don't want to do that).

My idea was to convert all the values from their currency format to a standard double and store that instead. Then just re-format based on the culture info when displaying. However, I have tried doing something like e.g.

var cultureInfo = new System.Globalization.CultureInfo("en-US");
double plain = return Double.Parse("$20,000.00", cultureInfo);

This doesn't ever seem to work it always throws a FormatException. Even removing the currency symbol and just trying to do this based on the number alone does the same thing. This is just an example I want to support pretty much any type of currency.

Is there a standard way of stripping out currency and getting the value as a double?

Answer 1

I think this should work:

double.Parse(currencyValue, NumberStyles.Currency);

Here you can see more about the NumberStyles.

Edit: In case anyone sees this answer without looking at the other answers/comments, this answer answered the question as written, but storing currency as a double is not a good idea, and it would be better to use decimal instead.

Answer 2

You should pass NumberStyles to the Parse function

Decimal.Parse("$20,000.00", NumberStyles.AllowCurrencySymbol | NumberStyles.AllowDecimalPoint | NumberStyles.AllowThousands, new CultureInfo("en-US"));

A few other things, for currencies I would suggest you use Decimal. And this might be way off, but it might be better to store the currency data as Money in the DB and add a currency code to identify the currency of the value.

Yes, and the answers suggestung NumberStyles.Currency that would be better. It is a pre-Or'd value, if you still think you want to use the strings.

Answer 3

You can also use the tryparse()

string input = "$2,000.00";
double parsed = 0d;
double.TryParse(input, NumberStyles.AllowCurrencySymbol | NumberStyles.AllowDecimalPoint | NumberStyles.AllowThousands, CultureInfo.CurrentCulture, out parsed))