从自定义日期swift设置明天日期

Question

我有一个应用程序,用户可以从中选择日期.如何从所选日期设置明天日期.例如,如果用户选择日期24,则打印25,如果用户选择日期31,则打印1.

现在我正在使用当前日期来设置明天的日期

let dates = Date()
var tomorrow: Date {
    return Calendar.current.date(byAdding: .day, value: 1, to: Date())!
}         

let dateFormatter = DateFormatter()
dateFormatter.dateFormat = "dd"

let dateOutDefault = dateFormatter.string(from: tomorrow as Date)

如何使用自定义日期做这样的事情？

Answer 1

import Foundation

extension Date {

    var tomorrow: Date? {
        return Calendar.current.date(byAdding: .day, value: 1, to: self)
    }
}

let today = Date()

let dateFormatter = DateFormatter()
dateFormatter.dateFormat = "MMM dd, yyyy, HH:mm b"

if let tomorrow = today.tomorrow {
    let tomorrowString = dateFormatter.string(from: tomorrow)
    print("\(tomorrowString)" // "Mar 23, 2017, 00:14 AM\n"
}