Swift - 獲取下一個日期

Question

我正在嘗試編寫一個函數，它接受一個字符串（格式爲「dd MM yyyy」）並返回給定參數之後的那一天。

例如：

let nextDay = getNextDay("31 12 2016") 
print(nextDay) 

將打印：

01 01 2017 

有人能告訴我如何做到這一點？謝謝

Answer 1

這裏的代碼片段可能會幫助你。

//Call method like this 

convertNextDate(dateString: "31 12 2016") 


// Method is here 

func convertNextDate(dateString : String){  
    let dateFormatter = DateFormatter() 
    dateFormatter.dateFormat = "dd MM yyyy" 
    let myDate = dateFormatter.date(from: dateString)! 
    let tomorrow = Calendar.current.date(byAdding: .day, value: 1, to: myDate) 
    let somedateString = dateFormatter.string(from: tomorrow!) 
    print("your next Date is \(somedateString)") 
} 

Answer 2

class DateHelper 
{ 

    lazy var formatter:DateFormatter = { 
    let formatter = DateFormatter() 
    formatter.dateFormat = "dd MM yyyy" 
    return formatter 
}() 

    lazy var dateComponents:DateComponents = { 
    var dateComp = DateComponents() 
    dateComp.day = 1 
    return dateComp 
}() 

    func getNext(dateString:String) -> String? 
    { 
    if let date  = self.formatter.date(from: dateString), 
     let nextDate = Calendar.current.date(byAdding: self.dateComponents, to: date) 
    { 
     return self.formatter.string(from: nextDate) 
    } 
    return nil 
    } 
} 

DateHelper().getNext(dateString: "31 12 2016")