iosswiftnsnumberformatter

Convert string to number using NumberFormatter not returning expected number


let formatter = NumberFormatter()
let sample1 = formatter.number(from: "29.99") ---> 29.99
let sample2 = formatter.number(from: "79.99") ---> 79.98999999999999

But I expect to get 79.99 as the result of sample2

Tried using different rounding modes with no help


Solution

  • This happens because a Floating Point Number. You can see what is FPN in here

    If you need 2 decimal value with round , you can use this extension link

    extension NSNumber {
        func rounded(to decimalPlaces: Int) -> Double {
            let multiplier = pow(10, Double(decimalPlaces))
    
        return (Double(truncating: self) * multiplier).rounded(.toNearestOrEven) / multiplier
        }
    }
    
      let sample1 = formatter.number(from: "29.99")?.rounded(to: 2) --> will be Optional(29.99)
      let sample2 = formatter.number(from: "79.99")?.rounded(to: 2) --> will be Optional(79.99)