conversion from NSTimeInterval to hour,minutes,seconds,milliseconds in swift

Question

My code is here:

func stringFromTimeInterval(interval:NSTimeInterval) -> NSString {

    var ti = NSInteger(interval)
    var ms = ti * 1000
    var secon         


        

Answer 1

Here is slightly improved version of @maslovsa's, with Precision input param:

import Foundation

extension TimeInterval {

    enum Precision {
        case hours, minutes, seconds, milliseconds
    }

    func toString(precision: Precision) -> String? {
        guard self > 0 && self < Double.infinity else {
            assertionFailure("wrong value")
            return nil
        }

        let time = NSInteger(self)

        let ms = Int((self.truncatingRemainder(dividingBy: 1)) * 1000)
        let seconds = time % 60
        let minutes = (time / 60) % 60
        let hours = (time / 3600)

        switch precision {
        case .hours:
            return String(format: "%0.2d", hours)
        case .minutes:
            return String(format: "%0.2d:%0.2d", hours, minutes)
        case .seconds:
            return String(format: "%0.2d:%0.2d:%0.2d", hours, minutes, seconds)
        case .milliseconds:
            return String(format: "%0.2d:%0.2d:%0.2d.%0.3d", hours, minutes, seconds, ms)
        }
    }
}

and usage:

let time: TimeInterval = (60 * 60 * 8) + 60 * 24.18
let hours = time.toString(precision: .hours) // 08
let minutes = time.toString(precision: .minutes) // 08:24
let seconds = time.toString(precision: .seconds) // 08:24:10
let milliseconds = time.toString(precision: .milliseconds) // 08:24:10.799