objective c - Find locale currency for iphone programmatically

Question

I want to find out the currency locale on user's iphone programmatically. That means, if user is in US Store, the currency locale should be USD, for Australia, it should be AUD. My purpose of this task is to try to convert the item price listed on our app to be nearly match with the price that AppStore ask.

For example, if we sell a video 3 usd, and an Australian wants to buy it, then I should show 2.8 AUD in my app screen. It will reduce the calculation in the user over the real price in his country. Does anybody know how to do it?

Answer 1

In most cases the currency symbol won't be enough. For example, in Germany we write our prices like this: 1,99€ but people in the US use $1.99. There are three differences in the string. The currency symbol, the position of it and the separator.

If you want to do it right you should use a NSNumberFormatter. It takes care of all the differences between currency formats. And it does it much better than you. Because it does it for all currencies, not just for the 4 main currencies you want to support.

NSNumberFormatter *formatter = [[NSNumberFormatter alloc] init];
[formatter setNumberStyle:NSNumberFormatterCurrencyStyle];
[formatter setLocale:[NSLocale currentLocale]];
NSString *localizedMoneyString = [formatter stringFromNumber:myCurrencyNSNumberObject];

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If you want to use this for in app purchase you can't rely on the users current locale, because it is possible to use a US-based account on a device with a DE (german) locale. And the price of your item (actual price is 0,79€ in Germany) would show as 0,99€ (because it costs $0.99 in the US). This would be wrong. You get a localized price already from the app store, there is no need to do calculations on your own.
And you get a price and a priceLocale for each of your SKProducts.

You would get the correct formatted currency string like this:

SKProduct *product = [self.products objectAtIndex:indexPath.row];
NSNumberFormatter *formatter = [[[NSNumberFormatter alloc] init] autorelease];
[formatter setNumberStyle:NSNumberFormatterCurrencyStyle];
[formatter setLocale:product.priceLocale];
currencyString = [formatter stringFromNumber:product.price];

EDIT: since you specifically asked for the currency code.

You can get it with NSString *currencyCode = [formatter currencyCode]; This will give you the currency code according to ISO 4217. AUD, USD, EUR and so on.