Swift Convert A String-As-An-Array, To An Array Of Strings

Question

I have a string:

"["word1","word2"]"

And I want a simple way to convert it to an actual [String].

All the other questions I could dig up on there were about converting int strings to arrays.

I tried doing

Array(arrayLiteral: "["word1","word2"]")

But I get

["[\"word1\",\"word2\"]"]

Manually cleaning up the edges and removing the slashes seems like I'm doing something very wrong.

I'm curious if there's a simple way to convert a an array of strings as a string into an array of strings.

i.e. Convert "["word1","word2"]" to ["word1","word2"]

Solution (Thanks to @Eric D)

    let data = stringArrayString.dataUsingEncoding(NSUTF8StringEncoding)

    var stringsArray:[String]!

    do
    {
        stringsArray = try NSJSONSerialization.JSONObjectWithData(data!, options: []) as? [String]
    } catch
    {
        print()
    }

    print("Array is \(stringsArray)")

My app uses Cordova, so this is a command coming from a Javascript interface. — Aggressor
– Aggressor, Commented Apr 20, 2016 at 0:37
@LeoDabus I could use SwiftyJSON but I am curious if theres a quick way built into swift where I can move directly to a string array from a string formatted as an array — Aggressor
– Aggressor, Commented Apr 20, 2016 at 0:38
There's stuff built in to Foundation, but not built into the Swift standard library as far as I know. — nhgrif
– nhgrif, Commented Apr 20, 2016 at 0:39

Eric Aya · Accepted Answer · 2016-04-20 10:42:56Z

3

Encode your "string array" to data, then decode this data as JSON to a Swift Array.

Like this, for example:

let source = "[\"word1\",\"word2\"]"

guard let data = source.dataUsingEncoding(NSUTF8StringEncoding),
    arrayOfStrings = try NSJSONSerialization.JSONObjectWithData(data, options: []) as? [String] else {
        fatalError()
}

print(arrayOfStrings)  // ["word1", "word2"]
print(arrayOfStrings[1])  // "word2"

answered Apr 20, 2016 at 10:42

Eric Aya

70.2k36 gold badges190 silver badges266 bronze badges

Sign up to request clarification or add additional context in comments.

3 Comments

Aggressor Over a year ago

Interesting I've not seen this syntax before! Could you name what

guard let data = source.dataUsingEncoding(NSUTF8StringEncoding),     arrayOfStrings = try NSJSONSerialization.JSONObjectWithData(data, options: [])

is called? I'd like to read up on this

Eric Aya Over a year ago

It's called a "guard statement" and you can read about it here: developer.apple.com/library/ios/documentation/Swift/Conceptual/… in the "Early exit" section of "Control Flow". It's an alternative to if let that lets you use the unwrapped value in the current scope. It's very convenient. :)

Aggressor Over a year ago

Very cool! Might want to update your answer to include the catch ;).

zpasternack · Accepted Answer · 2016-04-20 18:35:21Z

1

Agree with comments above, I'd probably use a JSON parser. Failing that (or if you can't for some reason), I do not know of any built-in way; you'd have to do it manually. I'd do something like:

extension String {
    func stringByTrimmingFirstAndLast() -> String {
        let startIndex = self.startIndex.successor()
        let endIndex = self.endIndex.predecessor()
        return self.substringWithRange( startIndex..<endIndex )
    }
}

let str = "[\"word1\",\"word2\"]"
let array = str
    .stringByTrimmingFirstAndLast()
    .componentsSeparatedByString(",")
    .map { string in
        return string.stringByTrimmingFirstAndLast()
    }

edited Apr 20, 2016 at 18:35

answered Apr 20, 2016 at 1:28

zpasternack

17.9k2 gold badges65 silver badges81 bronze badges

Collectives™ on Stack Overflow

Swift Convert A String-As-An-Array, To An Array Of Strings

2 Answers 2

3 Comments

Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

3 Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related