xcode - how to add commas to a number in swift?

Question

How would I add commas to a number that I'm retrieving from a JSON in swift.

Example
31908551587 to
31,908,551,587

I'm so confused and I have no idea what to do.

Answer 1

You can do it with NSNumberFormatter

Swift 4

let largeNumber = 31908551587
let numberFormatter = NumberFormatter()
numberFormatter.numberStyle = .decimal
let formattedNumber = numberFormatter.string(from: NSNumber(value:largeNumber))

Swift 3

 let largeNumber = 31908551587
 let numberFormatter = NumberFormatter()
 numberFormatter.numberStyle = NumberFormatter.Style.decimal
 let formattedNumber = numberFormatter.string(from: NSNumber(value:largeNumber))

Swift 2

 let largeNumber = 31908551587
 let numberFormatter = NSNumberFormatter()
 numberFormatter.numberStyle = NSNumberFormatterStyle.DecimalStyle
 let formattedNumber = numberFormatter.stringFromNumber(largeNumber)