如何从日期类型获取日期和月份-Swift 4

Question

我有数据类型为Date的变量，我以这种格式存储日期

  

2018-12-24 18:00:00 UTC

我从这一天或这个月如何得到？

Answer 1

如果您将“ 2018-12-24 18:00:00 UTC”另存为字符串，则可以尝试以下操作：

    let dateString = "2018-12-24 18:00:00 UTC"
    let formatter = DateFormatter()
    formatter.dateFormat = "yyyy-MM-dd HH:mm:ss 'UTC'"
    guard let date = formatter.date(from: dateString) else {
        return
    }

    formatter.dateFormat = "yyyy"
    let year = formatter.string(from: date)
    formatter.dateFormat = "MM"
    let month = formatter.string(from: date)
    formatter.dateFormat = "dd"
    let day = formatter.string(from: date)
    print(year, month, day) // 2018 12 24

最良好的祝愿！

Answer 2

该字符串或日期类型？

如果是约会，您可以这样做：

 let calanderDate = Calendar.current.dateComponents([.day, .year, .month], from: date)

这将为您提供年，月和日

Answer 3

日期字符串不符合ISO8601，但是如果将ISO8601DateFormatter替换为<space> + UTC并使用自定义格式选项，则可以使用Z。

从字符串中创建一个Date，并为DateComponents和day获得month

let string = "2018-12-24 18:00:00 UTC"

let formatter = ISO8601DateFormatter()
let trimmedString = string.replacingOccurrences(of: "\\s?UTC", with: "Z", options: .regularExpression)
formatter.formatOptions = [.withFullDate, .withFullTime, .withSpaceBetweenDateAndTime]
if let date = formatter.date(from: trimmedString) {
    let components = Calendar.current.dateComponents([.day, .month], from: date)
    let day = components.day!
    let month = components.month!
    print(day, month)
}

Answer 4

详细信息

• Xcode版本11.0（11A420a），Swift 5

链接

How to convert string to Date

解决方案

extension Date {
    func get(_ components: Calendar.Component..., calendar: Calendar = Calendar.current) -> DateComponents {
        return calendar.dateComponents(Set(components), from: self)
    }

    func get(_ component: Calendar.Component, calendar: Calendar = Calendar.current) -> Int {
        return calendar.component(component, from: self)
    }
}

用法

let date = Date()

// MARK: Way 1

let components = date.get(.day, .month, .year)
if let day = components.day, let month = components.month, let year = components.year {
    print("day: \(day), month: \(month), year: \(year)")
}

// MARK: Way 2

print("day: \(date.get(.day)), month: \(date.get(.month)), year: \(date.get(.year))")

Answer 5

这就是我在 swift 4 中所做的。我有一个 Billing 类，其中“billDate”是一个包含日期的字段。

extension Billing:Identifiable{
 func month() -> String {
    let dateFormatter = DateFormatter()
    dateFormatter.dateFormat = "MMM"
    
    if let inputDate = billDate {
        let month = dateFormatter.string(from: inputDate)
        
        return month.uppercased()
    }
    return ""
}