JSON data serialization in Swift

Question

I am new to Xcode and Swift, and I am trying to serialize JSON data from a url using the code below and get the error

'NSJSONReadingOptions' is not convertible to 'NSJSONWritingOptions'

on the line

var jsonResult = NSJSONSerialization.dataWithJSONObject(data, options: NSJSONReadingOptions.MutableContainers, error: nil)!

I cannot see my error, from online sources others use the same code and its works?

let task = session.dataTaskWithURL(loginUrl!, completionHandler: { (data, response, error) -> Void in
    if error != nil {
    }else {
        var jsonResult = NSJSONSerialization.dataWithJSONObject(data, options: NSJSONReadingOptions.MutableContainers, error: nil)!
        println(jsonResult)
    }
})

task.resume();

You're calling dataWithJSONObject which is used for serializing array/dictionary into JSON stored in a NSData object. But you want to call JSONObjectWithData, to deserialize JSON stored in NSData into an array/dictionary. The NSJSONReadingOptions is used with JSONObjectWithData. So, the problem isn't the NSJSONReadingOptions, but rather the fact that you called dataWithJSONObject instead of JSONObjectWithData. — Rob
– Rob, Commented May 17, 2015 at 23:38

rmaddy · Accepted Answer · 2015-05-17 23:14:15Z

1

Read the docs for dataWithJSONObject. The options parameter needs to be a value from the NSJSONWritingOptions enum, not the NSJSONReadingOptions enum.

But if your goal here is to convert an NSData object to an NSArray or NSDictionary, then the problem is that you are calling the wrong method. You want to use JSONObjectWithData, not dataWithJSONObject.

answered May 17, 2015 at 23:14

rmaddy

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1 Comment

emabusi Over a year ago

Thanks.. Solve my problem

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