Can I get exactly opposite result of NumberFormatter.Style.spellOut?

Question

I want "eleven" to 11 and I am not getting the result through::

formatter.number(from: "String")

Answer 1

The .spellOut style option of NumberFormatter works in both ways.

Note that if you want to parse "eleven" you need to set the appropriate Locale:

formatter.locale = .init(identifier: "en_US")

Then you can reverse the formatting using the same formatter:

let formatter = NumberFormatter()
formatter.locale = .init(identifier: "en_US")
formatter.numberStyle = .spellOut
if let number = formatter.number(from: "eleven") {
    print(number) // prints 11
} else {
    // error
}