CODEWITHSUNDEEP
swiftnsmutablearray
Joe C
Joe C

Reputation: 2834

Using NSMutableArray sortUsingFunction in Swift?

This link tells you what your sorting function has to look like, but I just can't make a Swift function look like that.

Here's my call:

packetsArray.sortUsingFunction(comparePacketDates, context: nil)

Here's my function, and I've tried a zillion other variations of it:

static func comparePacketDates(packet1 : AnyObject, packet2: AnyObject, context: UnsafeMutablePointer<Void>) -> Int {

And I've tried using a c function instead, this and a few other variations:

NSInteger comparePacketDates(id packet1, id packet2, void* dummy);

It's always "cannot invoke with argument list ..." saying the function isn't what's expected as the first argument.

Does anyone have example code of a Swift function that would be accepted as the first argument of the Swift sortUsingFunction? Or even a c function that would be accepted as the first argument of the Swift SortUsingFunction?

Upvotes: 2

Views: 677

Answers (2)

rob mayoff
rob mayoff

Reputation: 385600

Use sortUsingComparator. It's simpler than sortUsingFunction. Here's the syntax:

a.sortUsingComparator {
    let packet1 = $0 as! Packet
    let packet2 = $1 as! Packet
    if packet1.timestamp < packet2.timestamp {
        return .OrderedAscending
    }
    if packet1.timestamp == packet2.timestamp {
        return .OrderedSame
    }
    return .OrderedDescending
}

Upvotes: 4

Shripada
Shripada

Reputation: 6524

Here is an example for your reference that I wrote:

var ma = NSMutableArray()

ma.addObject("Hi")
ma.addObject("Anil")

func comp(first: AnyObject, second:AnyObject,  context: UnsafeMutablePointer<Void>) -> Int {
  let f:String  = first as! String
  let s:String = second as! String

  if f > s {
    return 1
  }
  else if ( f == s ) {
    return 0
  }

  return -1

}

ma.sortUsingFunction(comp, context:UnsafeMutablePointer<Void>(bitPattern: 0))

HTH, as a reference to you. Note: I am in Xcode 7.1 Swift 2.1.

Upvotes: 0

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