iOS Swift get Day of the Week example

import UIKit

func getDayOfWeek(_ date:String, format: String) -> String? {
    
    let weekDays = [
        "Sunday",
        "Monday",
        "Tuesday",
        "Wednesday",
        "Thursday",
        "Friday",
        "Saturday"
    ]

    let formatter  = DateFormatter()
    formatter.dateFormat = format
    guard let myDate = formatter.date(from: date) else { return nil }
    
    let myCalendar = Calendar(identifier: .gregorian)
    let weekDay = myCalendar.component(.weekday, from: myDate)
    
    
    return weekDays[weekDay-1]
}

//testing date1
if let weekday = getDayOfWeek("04/24/2019", format:"MM/dd/yyyy") {
    print(weekday)
} else {
    print("Invalid Date")
}
//Result = Wednesday

//testing date2
if let weekday = getDayOfWeek("2019-04-23", format:"yyyy-MM-dd") {
    print(weekday)
} else {
    print("Invalid Date")
}
//Result = Tuesday

//testing date3
if let weekday = getDayOfWeek("2019-04-23", format:"MM/dd/yyyy") {
    print(weekday)
} else {
   print("Invalid Date")
}
//Result = Invalid Date