¿Cómo obtener la hora (hora, minuto, segundo) en Swift 3 usando NSDate?

¿Cómo puede determinar la hora, minuto y segundo de la clase NSDate en Swift 3?

En Swift 2:

let date = NSDate()
let calendar = NSCalendar.currentCalendar()
let components = calendar.components(.Hour, fromDate: date)
let hour = components.hour

Swift 3?

En Swift 3.0, Apple eliminó el prefijo 'NS' y simplificó todo. A continuación se muestra la forma de obtener la hora, los minutos y los segundos de la clase 'Fecha' (alternativa NSDate)

let date = Date()
let calendar = Calendar.current

let hour = calendar.component(.hour, from: date)
let minutes = calendar.component(.minute, from: date)
let seconds = calendar.component(.second, from: date)
print("hours = \(hour):\(minutes):\(seconds)")

Como estos, puede obtener era, año, mes, fecha, etc. pasando correspondiente.

Swift 4.2 y 5

// *** Create date ***
let date = Date()

// *** create calendar object ***
var calendar = Calendar.current

// *** Get components using current Local & Timezone ***
print(calendar.dateComponents([.year, .month, .day, .hour, .minute], from: date))

// *** define calendar components to use as well Timezone to UTC ***
calendar.timeZone = TimeZone(identifier: "UTC")!

// *** Get All components from date ***
let components = calendar.dateComponents([.hour, .year, .minute], from: date)
print("All Components : \(components)")

// *** Get Individual components from date ***
let hour = calendar.component(.hour, from: date)
let minutes = calendar.component(.minute, from: date)
let seconds = calendar.component(.second, from: date)
print("\(hour):\(minutes):\(seconds)")

Swift 3.0

// *** Create date ***
let date = Date()

// *** create calendar object ***
var calendar = NSCalendar.current

// *** Get components using current Local & Timezone ***    
print(calendar.dateComponents([.year, .month, .day, .hour, .minute], from: date as Date))

// *** define calendar components to use as well Timezone to UTC ***
let unitFlags = Set<Calendar.Component>([.hour, .year, .minute])
calendar.timeZone = TimeZone(identifier: "UTC")!

// *** Get All components from date ***
let components = calendar.dateComponents(unitFlags, from: date)
print("All Components : \(components)")

// *** Get Individual components from date ***
let hour = calendar.component(.hour, from: date)
let minutes = calendar.component(.minute, from: date)
let seconds = calendar.component(.second, from: date)
print("\(hour):\(minutes):\(seconds)")

let date = Date()       
let units: Set<Calendar.Component> = [.hour, .day, .month, .year]
let comps = Calendar.current.dateComponents(units, from: date)

Rápido 4

    let calendar = Calendar.current
    let time=calendar.dateComponents([.hour,.minute,.second], from: Date())
    print("\(time.hour!):\(time.minute!):\(time.second!)")

En Swift 3 puedes hacer esto,

let date = Date()
let hour = Calendar.current.component(.hour, from: date)

let hours = time / 3600
let minutes = (time / 60) % 60
let seconds = time % 60
return String(format: "%0.2d:%0.2d:%0.2d", hours, minutes, seconds)

Rápido 5+

extension Date {
    
    func get(_ type: Calendar.Component)-> String {
        let calendar = Calendar.current
        let t = calendar.component(type, from: self)
        return (t < 10 ? "0\(t)" : t.description)
    }
}

Uso:

print(Date().get(.year)) // => 2020
print(Date().get(.month)) // => 08
print(Date().get(.day)) // => 18 

Para mayor utilidad creo esta función:

func dateFormatting() -> String {
    let date = Date()
    let dateFormatter = DateFormatter()
    dateFormatter.dateFormat = "EEEE dd MMMM yyyy - HH:mm:ss"//"EE" to get short style
    let mydt = dateFormatter.string(from: date).capitalized

    return "\(mydt)"
}

Simplemente llámalo donde quieras así:

print("Date = \(self.dateFormatting())")

esta es la salida:

Date = Monday 15 October 2018 - 17:26:29

si quieres solo el tiempo simplemente cambia:

dateFormatter.dateFormat  = "HH:mm:ss"

y esta es la salida:

Date = 17:27:30

y eso es...

swift 4

==> Getting iOS device current time:-

print(" ---> ",(Calendar.current.component(.hour, from: Date())),":",
               (Calendar.current.component(.minute, from: Date())),":",
               (Calendar.current.component(.second, from: Date())))

output: ---> 10 : 11: 34

Esto puede resultar útil para quienes deseen utilizar la fecha actual en más de una clase.

extension String {


func  getCurrentTime() -> String {

    let date = Date()
    let calendar = Calendar.current


    let year = calendar.component(.year, from: date)
    let month = calendar.component(.month, from: date)
    let day = calendar.component(.day, from: date)
    let hour = calendar.component(.hour, from: date)
    let minutes = calendar.component(.minute, from: date)
    let seconds = calendar.component(.second, from: date)

    let realTime = "\(year)-\(month)-\(day)-\(hour)-\(minutes)-\(seconds)"

    return realTime
}

}

Uso

        var time = ""
        time = time.getCurrentTime()
        print(time)   // 1900-12-09-12-59