Limit a float number to two places after the decimal and also provide comma_separated format to the number in Swift

Question

I am having issues in limiting a Float number to two decimal places and also provide a comma separated result in Swift. I have tried the following codes :

var myNum = 99.999999
myNum = (myNum * 100).rounded() / 100
print(myNum)
//Result : 100.0, Required_Result : 99.99



let formatted = String(format: "myNum: %.2f", myNum)
//Result : 100.00, Required_Result : 99.99

For eg: 1234.99999 should give the result as 1,234.99

For comma separation and Truncating to two decimal places I used :

 let numberFormatter = NumberFormatter()
 numberFormatter.maximumFractionDigits = 2
 numberFormatter.numberStyle = NumberFormatter.Style.decimal
 let formattedNumber = numberFormatter.string(from: NSNumber(value: number))
 return formattedNumber!

The above code is giving the following result : Number: 9999.9984 Result : 1,000.0 Required result: 9,999.99

Are you looking to always round toward zero as in `(myNum*100).rounded(.towardZero)/100`? — Joachim Isaksson, Dec 27 '18 at 07:22
@JoachimIsaksson I always want the next two digits after the decimal — Samarth Kejriwal, Dec 27 '18 at 07:26
@JoachimIsaksson One more thing, I want the number to be comma separated i.e. 1234.99999 should give me 1,234.99 — Samarth Kejriwal, Dec 27 '18 at 07:29
Possible duplicate of [Rounding a double value to x number of decimal places in swift](https://stackoverflow.com/questions/27338573/rounding-a-double-value-to-x-number-of-decimal-places-in-swift) — Magnas, Dec 27 '18 at 07:30
If you want decimal positions intact, why won't you just use [NSDecimalNumber](https://developer.apple.com/documentation/foundation/nsdecimalnumber)? — user28434'mstep, Dec 27 '18 at 11:29

score 2 · Answer 1 · edited Dec 27 '18 at 07:34

2

Use a NSNumberFormatterand configure its rounding mode accordingly:

    let formatter = NumberFormatter()
    formatter.maximumFractionDigits = 2
    formatter.roundingMode = .down
    let s = formatter.string(from: 99.99999)
    print(s as Any) //99.99

edited Dec 27 '18 at 07:34

Uma Madhavi

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answered Dec 27 '18 at 07:27

score 1 · Answer 2 · answered Dec 27 '18 at 07:42

Here is your solution you need to use NumberFormatter for this issue

var myNum = 9999.9998
myNum = (myNum * 100.0) / 100.0
print(myNum)

let currencyFormatter = NumberFormatter()
currencyFormatter.numberStyle = .decimal
currencyFormatter.maximumFractionDigits = 2
currencyFormatter.minimumFractionDigits = 2
currencyFormatter.roundingMode = .down
let s = currencyFormatter.string(from: NSNumber.init(value: myNum)) // NSNumber init with double
print(s ?? "0.0")

Mukesh · Answer 3 · 2018-12-27T11:13:28.430

For better precision you can use Float80 from Swift standard library.

Use it like this and you will get 9,999.99 result:

let myNum = 9999.9998
let floaNumber = Float80(Int(myNum*100))
let result = Double(floaNumber/100.0)
print(result)

let numberFormatter = NumberFormatter()
numberFormatter.numberStyle = .decimal

let formattedNumber = numberFormatter.string(from: NSNumber(value: result))
print(formattedNumber!)

Limit a float number to two places after the decimal and also provide comma_separated format to the number in Swift

3 Answers3