如何将NSDecimalNumber格式化为Swift字符串？

Question

If you have code such as this, then result will be "2.99":

let n = 2.99
let result = String(format: "%.2f", n)

However, if you have code like this:

    let nNS:NSDecimalNumber = 2.99
    let result2 = String(format: "%.2f", nNS)

Then result2 is "0.00".

How can you format an NSDecimalNumber into a string like this?

Answer 1

You can use a NumberFormatter to convert an NSNumber to a String.

let priceNS:NSDecimalNumber = 2.99
let nf = NumberFormatter()
nf.maximumFractionDigits = 2
nf.string(from: priceNS) //2.99

Answer 2

You should format your product price using NumberFormatter and use your product locale: https://developer.apple.com/documentation/storekit/skproduct/1506094-price

let numberFormatter = NumberFormatter()
numberFormatter.numberStyle = .currency 
numberFormatter.locale = someSKProduct.priceLocale
let formattedPrice = numberFormatter.string(from: someSKProduct.price) ?? ""