First, you need to convert your string to NSDate with its format. Then, you change the dateFormatter
to your simple format and convert it back to a String.
Swift 3
let dateString = "Thu, 22 Oct 2015 07:45:17 +0000"
let dateFormatter = DateFormatter()
dateFormatter.dateFormat = "EEE, dd MMM yyyy hh:mm:ss +zzzz"
dateFormatter.locale = Locale.init(identifier: "en_GB")
let dateObj = dateFormatter.date(from: dateString)
dateFormatter.dateFormat = "MM-dd-yyyy"
print("Dateobj: \(dateFormatter.string(from: dateObj!))")
The printed result is: Dateobj: 10-22-2015