arrays - 如果属性值存在于另一个对象数组中，则快速过滤对象数组

Question

我有两个对象数组，如下所示:

MeetingRoomSuggestions :

init(suggestionReason: String, organizerAvailability: String,
startTime: String, endTime: String, dStart: Date, availability: String,
emailAddress: String, displayName: String, roomEmail: String,
occupancy: Int, building: String)

和Bookings :

init(startTime: String, endTime: String, dStart: Date, organizer :
String, location : String, subject : String)

我希望能够过滤/排除 MeetingRoomSuggestion如果 dStart 来 self 的数组中的对象属性存在于 Bookings数组。

我的代码:

  let filteredArr = meetingRoomSuggestions.filter { meeting in
        return bookingArray!.contains(where: { booking in
            return booking.dStart == meeting.dStart
        })
    }

我还尝试过滤起始字符串 - 这在两者中都是相同的。当我在过滤前打印出两个数组时 - 你可以清楚地看到有一个预订存在相同的 dStart .我怎样才能排除这个？

使用代码过滤并打印出来后:

print("meetings:")
        for meeting in self.meetingRoomSuggestions {
            print(meeting.roomEmail)
            print(meeting.dStart)
            print(meeting.startTime)
        }
        print()
        print("bookings:")
        for booking in self.bookingArray! {
            print(booking.location)
            print(booking.dStart!)
            print(booking.start)
        }            

        print("filtered array: ", filteredArr)

        for items in filteredArr {
            print("email: ", items.roomEmail)
            print("dstart: ", items.dStart)
        }

返回:

    meetings:
FirstFloorTestMeetingRoom1@qubbook.onmicrosoft.com
2019-02-20 15:00:00 +0000
2019-02-20T15:00:00.0000000
GroundFloorTestMeetingRoom1@qubbook.onmicrosoft.com
2019-02-20 15:00:00 +0000
2019-02-20T15:00:00.0000000

bookings:
FirstFloorTestMeetingRoom1@qubbook.onmicrosoft.com
2019-02-20 15:00:00 +0000
2019-02-20T15:00:00.0000000
gfprojectroom1@qubbook.onmicrosoft.com
2019-02-21 10:00:00 +0000
2019-02-21T10:00:00.0000000
gfprojectroom1@qubbook.onmicrosoft.com
2019-02-21 16:00:00 +0000
2019-02-21T16:00:00.0000000

filtered array:  [QUBook.MeetingSuggestion, QUBook.MeetingSuggestion]
email:  FirstFloorTestMeetingRoom1@qubbook.onmicrosoft.com
dstart:  2019-02-20 15:00:00 +0000
email:  GroundFloorTestMeetingRoom1@qubbook.onmicrosoft.com
dstart:  2019-02-20 15:00:00 +0000

由于某种原因，过滤后的数组与原始数组相同meetingRoomSuggestions array - 它不会过滤掉具有相同 dStart 的对象的出现.我怀疑过滤器有问题？我以前能够通过将对象数组与字符串数组等进行比较来过滤对象数组，但不是这样。

Answer 1

您在这里使用了某种反向逻辑。你应该做的是:

let filteredArr = meetingRoomSuggestions.filter { meeting in
    return !bookingArray.contains(where: { booking in
        return booking.dStart == meeting.dStart
    })
}

用简单的英语来说:过滤 session ，留下那些不 的dStart 值等于dStart bookingArray 中任何对象的值。