Swift: Parsing Arrays out of JSONs - arrays

Question

[{"name":"Air Elemental","toughness":"4","printings":["LEA","BTD","7ED","8ED","9ED","10E","DD2","M10","DPA","ME4","DD3_JVC"]}]
I have a JSON where there is an array in each listing called "printings" as seen below, how would I take this array out of each listing and convert it into a string like "LEA-BTD-7ED". Here is what I have so far but its crashing.
let err : NSErrorPointer?
let dataPath = NSBundle.mainBundle().pathForResource("cardata", ofType: "json")
let data : NSData = try! NSData(contentsOfFile: dataPath! as String, options: NSDataReadingOptions.DataReadingMapped)
do{
var contents = try NSJSONSerialization.JSONObjectWithData(data, options: NSJSONReadingOptions.AllowFragments) as! [AnyObject]
for var i = 0;i<contents.count;++i{
let printing = contents[i]["printings"] as! String
}
}

Answer 1

Here's the code:
let path = dataPath!
if let JSONData = NSData(contentsOfFile: path)
{
do
{
if let dictionariesArray = try NSJSONSerialization.JSONObjectWithData(JSONData, options: NSJSONReadingOptions()) as?
[[String: AnyObject]]
{
for dictionary in dictionariesArray
{
if let printingsArray = dictionary["printings"] as? [String]
{
let printingsString = printingsArray.joinWithSeparator("-")
print(printingsString)
}
}
}
}
catch
{
print("Could not parse file at \(path)")
}
}
Executing it prints "LEA-BTD-7ED-8ED-9ED-10E-DD2-M10-DPA-ME4-DD3_JVC"

Answer 2

You can't cast an Array (contents[i]["printings"]) to a String. What you want is Array's joinWithSeparator() method, like this:
let printing = contents[i]["printing"] as! Array
let printingStr = printing.joinWithSeparator("-")
(Actually, I'm not sure whether you need the as! Array; try it without it.)