Swift 按日期数组映射数组

Question

我正在尝试完成此任务：[ 但我必须按 NSDate 数组排序。

// dates are actual NSDates, I pasted strings into my sample
var dates:[NSDate] = [2019-12-20 13:00 +0000, 2019-12-20 13:00 +0000, 2019-12-12 13:00 +0000]
var people:[String] = ["Harry", "Jerry", "Hannah"]
var peopleIds:[Int] = [1, 2, 3, 4]


// the following line doesn't work.
// i tried a few variations with enumerated instead of enumerate and sorted instead of sort
// but with now luck
let sortedOrder = dates.enumerate().sort({[=11=].1>.1}).map({[=11=].0})

dates = sortedOrder.map({points[[=11=]]})
people = sortedOrder.map({people[[=11=]]})
peopleIds = sortedOrder.map({peopleIds[[=11=]]})

Answer 1

将您的日期声明从 NSDate 更改为 Date。 Date 自 Swift 3.0 起符合 Comparable 协议。这样做您可以简单地对日期进行排序 dates.sorted(by: >)。要将数组排序在一起，您可以压缩数组，按日期排序并映射排序的元素：

let sortedZip = zip(dates, zip(people, peopleIds)).sorted { [=10=].0 > .0}
let sortedPeople = sortedZip.map{ [=10=].1.0 }
let sortedIDs = sortedZip.map{ [=10=].1.1 }

Answer 2

如果您正在尝试对关联字段进行排序，您应该真正考虑使用某种模型的面向对象方法，但是，以下方法应该可以实现您正在尝试做的事情：

var n = min(dates.count, people.count, peopleIds.count)
var tuples = (0 ..< n).map { (dates[[=10=]], people[[=10=]], peopleIds[[=10=]]) }
    .sorted { [=10=].0 as Date > .0 as Date }
dates = tuples.map{ [=10=].0 }
people = tuples.map{ [=10=].1 }
peopleIds = tuples.map{ [=10=].2 }

Swift 按日期数组映射数组

Swift Map ARRAYS by Date Array

ios

swift

swift3