How to truncate decimals to x places in Swift
You can tidy this up even more by making it an extension of Double:
extension Double { func truncate(places : Int)-> Double { return Double(floor(pow(10.0, Double(places)) * self)/pow(10.0, Double(places))) }}You use it like this:
var num = 1.23456789// return the number truncated to 2 placesprint(num.truncate(places: 2))// return the number truncated to 6 placesprint(num.truncate(places: 6))
I figured this one out.
Just floor (round down) the number, with some fancy tricks.
let x = 1.23556789let y = Double(floor(10000*x)/10000) // leaves on first four decimal placeslet z = Double(floor(1000*x)/1000) // leaves on first three decimal placesprint(y) // 1.2355print(z) // 1.235So, multiply by 1 and the number of 0s being the decimal places you want, floor that, and divide it by what you multiplied it by. And voila.