Separate numbers into commas for each three digits (in Japanese yen)

I tried to find out how to divide the Japanese Yen by 3 digits, as in the Japanese Yen display.
It's like 123,456,789 yen or something like that.

	import UIKit

	class ViewController: UIViewController {

	override func viewDidLoad() {
	super.viewDidLoad()

	print(addComma(num: 123456789) + "円") //->123,456,789円
	}

	func addComma(num:NSInteger) -> String {
	let formatter = NumberFormatter()
	formatter.numberStyle = NumberFormatter.Style.decimal
	formatter.groupingSeparator = ","
	formatter.groupingSize = 3

	let numnum = NSNumber(value: num)
	let str = formatter.string(from: numnum)!
	return str
	}
	}