Getting the decimal part of a double in Swift

4 Solutions Collect From Internet About “Getting the decimal part of a double in Swift”

Without converting it to a string, you can round up to a number of decimal places like this:

let x:Double = 1234.5678
let numberOfPlaces:Double = 4.0
let powerOfTen:Double = pow(10.0, numberOfPlaces)
let targetedDecimalPlaces:Double = round((x % 1.0) * powerOfTen) / powerOfTen

Your output would be

0.5678

You can use truncatingRemainder and 1 as the divider.

Returns the remainder of this value divided by the given value using truncating division.

Apple doc

Example:

let myDouble1: Double = 12.25
let myDouble2: Double = 12.5
let myDouble3: Double = 12.75

let remainder1 = myDouble1.truncatingRemainder(dividingBy: 1)
let remainder2 = myDouble2.truncatingRemainder(dividingBy: 1)
let remainder3 = myDouble3.truncatingRemainder(dividingBy: 1)

remainder1 -> 0.25
remainder2 -> 0.5
remainder3 -> 0.75

Use Float since it has less precision digits than Double

let x:Double = 1234.5678
let n1:Float = Float(x % 1)           // n1 = 0.5678

Swift 2:

You can use:

modf(x).1

or

x % floor(abs(x))