Im trying to use this line of code:
func getFirstWeekDay() -> Int {
let day = ("\(currentYear)-\(currentMonthIndex)-01".date?.firstDayOfTheMonth.weekday)!
return day
}
but Im getting this error.. I dont know how else to write it.
Error: Cannot use optional chaining on non-optional value of type 'Any'
You have several errors. Where did you get the code from ?
First, you look for dtae property of a string :
"a string".date
There is no such property
Where did you define firstDayOfTheMonth ?
To get the date from a string, should use dateFormatter as here:
var dateFormatter = DateFormatter()
dateFormatter.dateFormat = "yyyy-MM-dd"
let currentYear = 2020
let currentMonthIndex = "01"
let day = dateFormatter.date(from: "\(currentYear)-\(currentMonthIndex)-01")!You set the day as 01. What the use to search for firstDaysOfTheMonth ?
You could also build the date through its components
let calendar = Calendar.current
var components = DateComponents()
components.day = 1
components.month = 1
components.year = 2020
let newDate = calendar.date(from: components)!Then you can get weekDay
components = calendar.dateComponents([.day, .month, .year, .weekday], from: newDate)
print("weekday:\(components.weekday!)")So, your func should become:
func getFirstWeekDay() -> Int {
var components = DateComponents()
components.day = 01
components.month = currentMonthIndex
components.year = currentYear
let theDate = calendar.date(from: components)!
components = calendar.dateComponents([.weekday], from: theDate)
return components.weekday!
}I advise you study Date class. This tutorial may help.
h ttp://ios-tutorial.com/working-dates-swift/
You have several errors. Where did you get the code from ?
First, you look for dtae property of a string :
"a string".date
There is no such property
Where did you define firstDayOfTheMonth ?
To get the date from a string, should use dateFormatter as here:
var dateFormatter = DateFormatter()
dateFormatter.dateFormat = "yyyy-MM-dd"
let currentYear = 2020
let currentMonthIndex = "01"
let day = dateFormatter.date(from: "\(currentYear)-\(currentMonthIndex)-01")!You set the day as 01. What the use to search for firstDaysOfTheMonth ?
You could also build the date through its components
let calendar = Calendar.current
var components = DateComponents()
components.day = 1
components.month = 1
components.year = 2020
let newDate = calendar.date(from: components)!Then you can get weekDay
components = calendar.dateComponents([.day, .month, .year, .weekday], from: newDate)
print("weekday:\(components.weekday!)")So, your func should become:
func getFirstWeekDay() -> Int {
var components = DateComponents()
components.day = 01
components.month = currentMonthIndex
components.year = currentYear
let theDate = calendar.date(from: components)!
components = calendar.dateComponents([.weekday], from: theDate)
return components.weekday!
}I advise you study Date class. This tutorial may help.
h ttp://ios-tutorial.com/working-dates-swift/
To get the date from a string, should use
as here:dateFormatter
Please don’t do this. Setting a
dateFormaten_US_POSIXYou could also build the date through its components
This is a much better approach.
This tutorial may help.
And, of course, that tutorial has the same problem *sigh*
Share and Enjoy
—
Quinn “The Eskimo!”
Apple Developer Relations, Developer Technical Support, Core OS/Hardware
let myEmail = "eskimo" + "1" + "@apple.com"I will definately look out for this. Thank you and thanks for the reference!!
This is from a old Swift 3 file that worked flawlessly but since updating it to Swift 4, 5 and doing the recommended fixes. It went haywire.
This is what I have defining the firstDayOfTheMonth:
Its also giving me these two errors:
'Declaration is only valid at file scope'
'Type 'String' has no member 'dateFormatter'
//get first day of the month
extension Date {
var weekday: Int {
return Calendar.current.component(.weekday, from: self)
}
var firstDayOfTheMonth: Date {
return Calendar.current.date(from: Calendar.current.dateComponents([.year,.month], from: self))!
}
}
//get date from string
extension String {
static var dateFormatter: DateFormatter = {
let formatter = DateFormatter()
formatter.dateFormat = "yyyy-MM-dd"
return formatter
}()
var date: Date? {
return String.dateFormatter.date(from: self)
}
}