Key-Value Coding (KVC) with Array/Dictionary in Swift

Question

Is it possible to key-value code (KVC) with native Swift data structures such as Array and Dictionary? Key-Value coding is still available for NSFoundation structures within Swift, just like in Objective C.

For example, this is valid:

var nsarray: NSArray = NSArray()
// Fill the array with objects
var array: NSArray = nsarray.valueForKeyPath("key.path")

But this is invalid:

var swiftarray: Array = []
// Fill the array with objects
var array = swiftarray.valueForKeyPath("key.path") // Invalid, produces a compile-time error

Coheman

do you mean swiftarray at the last line of code? – Proficient

Check out this post by Matt Long: cimgf.com/2014/11/05/… – Slack

Answer 1

It seems that KVC on native Swift objects is just not supported. Here's the most elegant workaround I've found:

var swiftarray: Array = []
// Fill the array with objects
var array: NSArray = (swiftarray as NSArray).valueForKeyPath("key.path") as NSArray

Coheman

Answer 2

I've found this:

var array = swiftarray.map({$0["key.path"]! as ObjectType})

Employment

Answer 3

you can do the following:

let items : Array<String> = (myArray as AnyObject).valueForKeyPath("name") as! Array<String>

Turmoil

Answer 4

How about this:

let names = array.map { $0.name }

Instead of using key paths you can directly refer to property or method.

Diplegia