I am trying to create an array of words from a string object retrieved from Parse. The object retrieved looks like this:
Then this line of code gives this.
let joinedWords = object["Words"] as! String
How do I convert joinedWords to an Array?
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2 Answers
If you don't care about the order, you can use flatMap on the set:
var mySet = Set<String>()
for index in 1...5 {
mySet.insert("testwords\(index)")
}
let myArray = mySet.flatMap { $0 }
print(myArray) // "["testwords5", "testwords3", "testwords4", "testwords2", "testwords1"]"
If you want the list sorted alphabetically, you can make your array a var and use sortInPlace()
var myArray = mySet.flatMap { $0 }
myArray.sortInPlace()
print(myArray) // "["testwords1", "testwords2", "testwords3", "testwords4", "testwords5"]"
If object["Words"] is AnyObject, you will have to unwrap it.
if let joinedWordsSet = object["Words"] as? Set<String> {
var joinedWordsArray = joinedWordsSet.flatMap { $0 }
myArray.sortInPlace()
print(myArray)
}
Swift 3 note: sortInPlace() has been renamed sort().
7 Comments
richc
ah, no it hasn't. I need to get the words that are in joinedWords string, not create a new set. How would I do that?
JAL
@richc It's not clear what you're asking. From your screenshot it looks like
Words is a set of Strings ("testwords1", "testwords2", ...). Are you trying to create a string with all of these words?richc
joinedWords is a set of strings in the form { (testword1, testword2, testword3, testword4, testword5)}. I need to convert that to an array in the form ["testword1", "testword2", "testword3", "testword4", "testword5"]. Order is not important for now. There can be any number of words.
JAL
@richc Right, so that's what my answer does. First declare
let joinedWords = object["Words"] as! Set<String>, then call flatMap on joinedWords like this: joinedWords.flatMap { $0 } to flatten the set into an array. If object["Words"] is not a Set, tell me what type it is by printing object["Words"].dynamicType.richc
print(object["Words"].dynamicType) gives ImplicitlyUnwrappedOptional<AnyObject> in console. Declaring joinedWords as a Set<String> crashes with Could not cast value of type '__NSCFString' (0x1e68da4) to 'NSSet' (0x1e697e0).
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Many thanks to @JAL for so much time on chat to solve this one. This is what we came up with. Its a bodge and no doubt there is a better way!
When uploading to Parse save the set as an array.
let wordsSet = (wordList?.words?.valueForKey("wordName"))! as! NSSet
let wordsArray = Array(wordsSet)
Then it saves to Parse - looking like a set, not an array or a dictionary.
let parseWordList = PFObject(className: "WordList")
parseWordList.setObject("\(wordsArray)", forKey: "Words")
parseWordList.saveInBackgroundWithBlock { (succeeded, error) -> Void in
if succeeded {
// Do something
} else {
print("Error: \(error) \(error?.userInfo)")
}
}
Then you can drop the [ ] off the string when its downloaded from Parse, and remove the , and add some "" and voila, there is an array that can be used e.g. to add to CoreData.
var joinedWords = object["Words"] as! String
joinedWords = String(joinedWords.characters.dropFirst())
joinedWords = String(joinedWords.characters.dropLast())
let joinedWordsArray = joinedWords.characters.split() {$0 == ","}.map{ String($0) } // Thanks @JAL!