Date conversion EEE MMM DD hh:mm:ss zzz YYYY

1. Create date conversion classification

//
//  Date+Extension.swift
//
import Foundation
extension Date{
    
    ///  Convert a formatted string to a date 
    static func fromData(string: String) ->Date?{
        let df = DateFormatter()
        df.locale = Locale(identifier: "en")
        df.dateFormat = "EEE MMM dd HH:mm:ss zzz yyyy"
        return df.date(from: string)
    }
    
    /**
         Return the multi description information of the current date 
         just ( In a minute )
        x Minutes ago ( In an hour )
        x Hours before ( same day )
         yesterday  HH:mm( yesterday )
        MM-dd HH:mm( Within a year )
        yyyy-MM-dd HH:mm( Earlier )
     */
    var dateDescription: String{
        // Take out the current calendar  -  Provides a large number of calendar related operation functions 
        let calendar =  Calendar.current
        // Process today's date 
        if calendar.isDateInToday(self) {
          let delta = Int(Date().timeIntervalSince(self))
            if delta < 60 {
                return " just "
            }
            if delta < 3600{
                return "\(delta/60)  Minutes ago "
            }
            
            return "\(delta/3600)  Hours before "
        }
        // Date not today 
        var fmt = " HH:mm"
        if calendar.isDateInYesterday(self){
            fmt = " yesterday " + fmt
        }else{
            fmt = "MM-dd" + fmt
            // Direct access to  “ year ” The numerical 
            let comps = calendar.dateComponents([.year], from: self, to: Date())
            if let year = comps.year, year > 0 {
                fmt = "yyyy-" +  fmt
            }
        }
        // Generate a description string according to the format string 
        let df = DateFormatter()
        df.dateFormat = fmt
        df.locale = Locale(identifier: "en")
        return df.string(from: self)
    }
}

2. The test method

    override func viewDidLoad() {
        super.viewDidLoad()
        // The goal is :  Special format string 
        // step 
        //1. establish  ‘ date ’ object 
        //2. According to the date object , Calculate and display description characters 
        let str = "Mon Jul 25 16:41:43 +0800 2022"
        print(Date.fromData(string: "Mon Jul 26 06:41:43 +0800 2022")?.dateDescription)
        print(Date.fromData(string: "Mon Jul 26 10:03:01 +0800 2022")?.dateDescription)
        print(Date.fromData(string: "Mon Jul 26 10:06:01 +0800 2022")?.dateDescription)
        print(Date.fromData(string: "Mon Jul 26 00:00:02 +0800 2022")?.dateDescription)
        
        print(Date.fromData(string: "Mon Jul 25 16:41:43 +0800 2022")?.dateDescription)
        print(Date.fromData(string: "Mon Jul 24 16:41:43 +0800 2022")?.dateDescription)
        print(Date.fromData(string: "Mon May 24 16:41:43 +0800 2022")?.dateDescription)
        print(Date.fromData(string: "Mon May 28 16:41:43 +0800 2021")?.dateDescription)
    }

3. Output results

Optional("3  Hours before ")
Optional("3  Minutes ago ")
Optional(" just ")
Optional("10  Hours before ")
Optional(" yesterday  16:41")
Optional("07-24 16:41")
Optional("05-24 16:41")
Optional("2021-05-28 16:41")