转换具有未知格式（任何格式）的字符串到目前为止 [英] Convert string with unknown format (any format) to date

问题描述

我的数据包含日期字符串。

I have data that contains a date string.

通常它会在'Jan. 1966年3月的'类型格式，但由于国际差异，它可能并不总是那样。

Normally it would be in a 'Jan. 3, 1966' type format, but because of international differences, it may not always be exactly that.

我需要读取数据并将其转换为标准日期字符串（'YYYY-MM-DD'）。

I need to read the data in and convert it into a standard date string ('YYYY-MM-DD').

基本上这就是我到目前为止：

Basically this is what I have so far:

var dataString = 'Jan. 3, 1966'  
var dateFormatter = NSDateFormatter()  
dateFormatter.dateFormat = # I DON'T KNOW THE EXACT INPUT FORMAT !
let dateValue = dateFormatter.dateFromString(dataString)  

推荐答案

Xcode 9•Swift 4 或 Xcode 8.3.2•Swift 3.1

您可以使用NSDataDetector如下：

You can use NSDataDetector as follow:

extension String {
    var nsString: NSString { return self as NSString }
    var length: Int { return nsString.length }
    var nsRange: NSRange { return NSRange(location: 0, length: length) }
    var detectDates: [Date]? {
        return try? NSDataDetector(types: NSTextCheckingResult.CheckingType.date.rawValue)
                .matches(in: self, range: nsRange)
                .flatMap{$0.date}
    }
}

extension Collection where Iterator.Element == String {
    var dates: [Date] {
        return flatMap{$0.detectDates}.flatMap{$0}
    }
}

测试：

let dateStrings = ["January 3, 1966","Jan 3, 1966", "3 Jan 1966"]
for dateString in dateStrings {
    if let dateDetected = dateString.detectDates?.first {
        print(dateDetected)
        // 1966-01-03 14:00:00 +0000
        // 1966-01-03 14:00:00 +0000
        // 1966-01-03 14:00:00 +0000
    }
}


let dateStrings = ["January 3, 1966","Jan 3, 1966", "3 Jan 1966"]

for date in dateStrings.dates {
    print(date)
    // 1966-01-03 14:00:00 +0000
    // 1966-01-03 14:00:00 +0000
    // 1966-01-03 14:00:00 +0000
}

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