Convert string with ordinal format to date on iOS

问题

Possible Duplicate:
Converting a string to an NSDate

---

I have date in string and want to convert in NSDate. In string date is:

"21st June 2012"

How can I convert this in NSDate?

Please concentrate on day "21st" not "21" when you give answer.

回答1:

You can use NSDateFormatter to change NSString to NSDate.

回答2:

There is a generic answer for this kind of questions available on Stack Overflow, it's to use NSDateFormatter in Objective-C / DateFormatter in Swift. And the format is following tr35-19 or newer according to Use Format Strings to Specify Custom Formats.

But to deal with your variation of a date format, here is the Swift answer for your specific requirements:

// Your example
let dateString = "21st June 2012"

// Sanitizing input for 2nd, 3rd, 4th
let normalizedDateString = dateString.replacingOccurrences(of: "nd", with: "st").replacingOccurrences(of: "rd", with: "st").replacingOccurrences(of: "th", with: "st")

// Converting string to date object
let formatter = DateFormatter()
formatter.locale = Locale(identifier: "en_US")
formatter.dateFormat = "d'st' MMMM yyyy"
let date = formatter.date(from: normalizedDateString)

Same logic in Objective-C.

来源：https://stackoverflow.com/questions/14600914/convert-string-with-ordinal-format-to-date-on-ios