Rounding Currency String - ios

Question

I was able to write this function as an extension method of NSDecimalNumber which worked out pretty well for me. It takes some number and formats it to the currency string. If it contains .00, it will truncate it, but if it's something like .23 or .45, it will retain the decimals.
func toCurrencyString() -> String
{
let nf = NSNumberFormatter()
nf.numberStyle = NSNumberFormatterStyle.CurrencyStyle
//Determine whether to show decimals or not (if trailing zeros exist, do not show)
if (trunc(self.floatValue) == self.floatValue) {
nf.maximumFractionDigits = 0
} else {
nf.maximumFractionDigits = 2
}
return nf.stringFromNumber(self)
}
I had a question:
How could implement a similar function above that returns a formatted string, but rounds it up? So something like 45.55 would be 46 (no decimals)
I tried using round() which works in playground, but when I use it extension methods, it says 'ambiguous use of round()'.
also..out of curiosity, is the above safe for different locales like it shows up for me perfectly in America, but if the user's phone was in the UK would it automatically work?
Thanks so much!

Answer 1

Took me a little bit but I got it:
func toRoundedCurrencyString() -> String
{
let nf = NSNumberFormatter()
nf.numberStyle = NSNumberFormatterStyle.CurrencyStyle
nf.maximumFractionDigits = 0
var roundingStyle = NSDecimalNumberHandler(roundingMode: NSRoundingMode.RoundBankers, scale: 0, raiseOnExactness: false, raiseOnOverflow: false, raiseOnUnderflow: false, raiseOnDivideByZero: false)
var roundedNumber = self.decimalNumberByRoundingAccordingToBehavior(roundingStyle)
return nf.stringFromNumber(roundedNumber)
}
Works well, but concerned with others said. I'm using NSDecimalNumber extension methods. Isn't NSDecimalNumber the preferred way to handle currency? btw i'm using currencies < 100,000 if that matters? Is it only larger currencies where it's a big deal? I'm always using up to 2 decimal places, if even.