Question

我在这里有一个数组：

[Type: Optional("web"), Date: Optional("1515970800"), 
Type: Optional("web"), Date: Optional("1515193200"), 
Type: Optional("web"), Date: Optional("1514847600"), 
Type: Optional("web"), Date: Optional("1514674800"), 
Type: Optional("twitter"), Date: Optional("1516590000"), 
Type: Optional("twitter"), Date: Optional("1516590000")]

这就是数组中的内容：

allData

类型和日期。

如何按Date过滤allData.sorted(by: { $0.date! < $1.date!})，以便最高的数字是第一个？

我试过了：

import UIKit

class feedStruct: NSObject {
    var type: String?
    var date: String?

    override init()
    {
    }

    //construct with @name, @address, @latitude, and @longitude parameters
    init(type: String, date: String) {
        self.type = type
        self.date = date
    }

    //prints object's current state
    override var description: String {
        return "Type: \(String(describing: type)), Date: \(String(describing: date))"
    }
}

但我收到错误：

Any类型的值没有成员日期

这是我的结构：

{{1}}

如何按日期值过滤？

Answer 1

I suppose you mean

How can I sort allData by the Date so the highest number is first

First of all I highly recommend to declare the custom object as struct with non-optional type and date and with an initializer which converts the UNIX timestamp to a Date instance. There is no need to use a class which inherits from NSObject and there is no need to use optionals.

struct Feed : CustomStringConvertible {

    let type: String
    let date: Date

    init(type : String, date : String) {
        self.type = type
        self.date = Date(timeIntervalSince1970: TimeInterval(date)!)
    }

    //prints object's current state

    var description: String {
        return "Type: \(type), Date: \(date))" // please do not misuse `String(describing:`

    }
}

Then declare your allData array as [Feed] (never as [Any], that's the error reason by the way)

var allData = [Feed]()

Populate the array with Feed instances

allData = [Feed(type: "web", date: "1515970800"),
         Feed(type: "web", date: "1515193200"),
         Feed(type: "web", date: "1514674800"),
         Feed(type: "web", date: "1516590000"),
         Feed(type: "twitter", date: "1516590000"),
         Feed(type: "twitter", date: "1515970800")]

and sort it by date descending

allData.sorted{ $0.date > $1.date }

Answer 2

var allData = ["15101001", "15250151", "11519501", "15192515"]
var convertedArray: [Date] = []

var dateFormatter = DateFormatter()
dateFormatter.dateFormat = "dd/MM/yyyy"

for dat in testArray {
var date = dateFormatter.date(from: dat)
convertedArray.append(date!)
}

//Method : 1
convertedArray.sort(){$0 < $1}    

//Method : 2
convertedArray.sorted(by: {$0.timeIntervalSince1970 < 
$1.timeIntervalSince1970})

print(convertedArray)

在Swift中的键中按数字过滤数组

2 个答案: