How to separate integral part and fractional part in Swift? An how to transform fractional part into Int

Question

I separated fractional part, but now I need to make that part as Int.

For example:

0.5 -> 5
0.63 -> 63

let a1 = 2.5
let a2 = 7.63
let a3 = 8.81
let a4 = 99.0
let a1Frac = a1.truncatingRemainder(dividingBy: 1)
let a2Frac = a2.truncatingRemainder(dividingBy: 1)
let a3Frac = a3.truncatingRemainder(dividingBy: 1)
let a4Frac = a4.truncatingRemainder(dividingBy: 1)

Leo Dabus · Accepted Answer · 2022-01-30T01:38:36.337

First you should use Swift Decimal type if you would like to preserve your fractional digits precision. Second to get its fraction value you can check this post. Once you have your decimal fractions all you need is to get their significand value:

extension Decimal {
    func rounded(_ roundingMode: NSDecimalNumber.RoundingMode = .bankers) -> Decimal {
        var result = Decimal()
        var number = self
        NSDecimalRound(&result, &number, 0, roundingMode)
        return result
    }
    var whole: Decimal { self < 0 ? rounded(.up) : rounded(.down) }
    var fraction: Decimal { self - whole }
}

let a1 = Decimal(string: "2.5")!
let a2 = Decimal(string: "7.63")!
let a3 = Decimal(string: "8.81")!
let a4 = Decimal(string: "99")!

let a1Frac = a1.fraction  // 0.5
let a2Frac = a2.fraction  // 0.63
let a3Frac = a3.fraction  // 0.81
let a4Frac = a4.fraction  // 0

let a1significand = a1Frac.significand  // 5
let a2significand = a2Frac.significand  // 63
let a3significand = a3Frac.significand  // 81
let a4significand = a4Frac.significand  // 0

If you need to convert your Decimal values to Int you can simply cast it to NSDecimalNumber and get its intValue or add those extensions to your project to add the same NSDecimalNumber functionality to Swift Decimal type:

extension Decimal {
    var decimalNumber: NSDecimalNumber { self as NSDecimalNumber}
    var intValue: Int { decimalNumber.intValue }
}

a1significand.intValue  // 5
a2significand.intValue  // 63
a3significand.intValue  // 81
a4significand.intValue  // 0

How to separate integral part and fractional part in Swift? An how to transform fractional part into Int

1 Answers1