Convert One Date Format To Another Date Format Swift 4 - iOS

Converting a date string from one date format to another date format is an easy by using the following method:

Date Formats:

Following are the some Date Formats:

Thursday, Oct 12, 2017 - EEEE, MMM d, yyyy
10/12/2017 - MM/dd/yyyy
10-12-2017 09:48 - MM-dd-yyyy HH:mm
Oct 12, 9:48 AM - MMM d, h:mm a
October 2017 - MMMM yyyy
Oct 12, 2017 - MMM d, yyyy
Thu, 12 Oct 2017 09:48:59 +0000 - E, d MMM yyyy HH:mm:ss Z
2017-10-12T09:48:59+0000 - yyyy-MM-dd'T'HH:mm:ssZ
12.10.17 - dd.MM.yy

For more check here.

One Date Format To Another:

For converting we are going to create String extension as follow:

extension String
{
    func toDateString( inputDateFormat inputFormat  : String,  ouputDateFormat outputFormat  : String ) -> String
    {
        let dateFormatter = DateFormatter()
        dateFormatter.dateFormat = inputFormat
        let date = dateFormatter.date(from: self)
        dateFormatter.dateFormat = outputFormat
        return dateFormatter.string(from: date!)
    }
}

Usage:

Add the following lines of code for usage:

let dateString = "2017-10-10 15:56:25"
let requiredFormat = dateString.toDateString(inputDateFormat: "yyyy-MM-dd HH:mm:ss", ouputDateFormat: "dd 'at' hh:mm:ss")
print(requiredFormat)

//output will be '10 at 03:56:25'

The inputDateFormat should be same as dateString, but the ouputDateFormat can be different as we required.