change JSON to String in Swift

Question

I got JSON file from API but the content looks like this:

[
  "https:\/\/seekingalpha.com\/article\/4125943-apple-homepod-delay-big-deal?source=feed_symbol_AAPL"
]

Suppose the JSON Object above is named as json. Then I just convert the object to string using String() method.
strings = String(json)
When I changed it to String type, it seems to get unnecessary '\n' and whitespace in it.

"[\n  \"https:\\/\\/seekingalpha.com\\/article\\/4125943-apple-homepod-delay-big-deal?source=feed_symbol_AAPL\"\n]"

So it seems like the content of the JSON file is:

["\n""whitespace""whitespace""String""\n"]

When I changed it to String type, Swift just treats all the elements in it as a whole and wrapped it as a string. My question is, how to extract the String inside so it looks like:

"https:\\/\\/seekingalpha.com\\/article\\/4125943-apple-homepod-delay-big-deal?source=feed_symbol_AAPL\"

As I am not so familiar with Swift so how to extract String or JSON Object is not easy for me. Any hints or help will be appreciated.

Show some code on how you are trying to convert it to a string. — Simon, Nov 19 '17 at 03:50
Why would you convert your JSON to String in the first place? You don't need to do that. Just decode the JSON *data* using one of the usual tools: JSONSerialization, SwiftyJSON, JSON Decoder... — Eric Aya, Nov 19 '17 at 12:57

score 0 · Answer 1 · answered Nov 19 '17 at 04:20

1. You will first have to convert JSON to Data
2. Convert data to string wrt to encoding    

    func jsonToString(jsonTOConvert: AnyObject){
        do {
            let data =  try JSONSerialization.data(withJSONObject: jsonTOConvert, options: JSONSerialization.WritingOptions.prettyPrinted) 
            let convertedString = String(data: data, encoding: String.Encoding.utf8) 
        } catch let myJSONError {
            print(myJSONError)
        }

}

score 0 · Answer 2 · answered Nov 19 '17 at 04:22

You are asking that a String be created with the contents:

[
  "https:\/\/seekingalpha.com\/article\/4125943-apple-homepod-delay-big-deal?source=feed_symbol_AAPL"
]

The string object is doing exactly what you told it to — the thing you've asked it to represent begins with a square bracket, then there's a line break, then two spaces, etc, so the string contains a square bracket, then a line break, then two spaces, etc. There is no 'unnecessary' \n, there is only the \n you told it to put in.

If you obtained a JSON object then you need to parse it as JSON. JSONSerialization will do that job. What you've actually got is an array with a single item, which is a string. So JSONSerialization will return an array. The first item of that should be a string that is the seekingalpha.com URL.

Rajamohan S · Accepted Answer · 2017-11-19T05:30:23.663

Swift 3,4 :

The given JSON format is Array of String.

if let json = try? JSONSerialization.jsonObject(with: data, options: .allowFragments) as? [String]{

        let firstElement = json?.first ?? "Element Not Found!"

        print(firstElement)
}

Swift 4:

if let json = try? JSONDecoder().decode(Array<String>.self, from: data){

    let firstElement = json.first ?? "First Element Not Found!"
    print(firstElement)
}

Note: If your the Array contains more than one String. Here,urls is the class variable. i.e.,var urls = [String]()

Swift 3,4 :

if let json = try? JSONSerialization.jsonObject(with: data, options: .allowFragments) as? [String]{

    if json != nil{

        self.urls = json!
    }

    print(self.urls)
}

Swift 4:

if let json = try? JSONDecoder().decode(Array<String>.self, from: data){

    self.urls = json
}

Really informative answer, I appreciate it!!!! Thanks a lot!!!! — Mark Dong, Nov 19 '17 at 21:46

change JSON to String in Swift

3 Answers3