Gabriel Bergamo Gabriel Bergamo - 1 year ago 309
iOS Question

NSJSONSerialization.JSONObjectWithData Returns nil

[
{
"_id": "557f27522afb79ce0112e6ab",
"endereco": {
"cep": "asdasd",
"numero": "asdasd"
},
"categories": [],
"name": "teste",
"hashtag": "teste"
}
]


Returns nil without error :

var json = NSJSONSerialization.JSONObjectWithData(data, options:NSJSONReadingOptions.AllowFragments, error: &erro) as? NSDictionary

Rob Rob
Answer Source

It's returning nil without error because it's not the JSON parsing that's failing. It's failing because of the conditional type cast of the resulting object as a dictionary. That JSON doesn't represent a dictionary: It's an array with one item (which happens to be a dictionary). The outer [ and ] indicate an array. So, when you parse this, you want to cast it as a NSArray.

For example, in Swift 1.2 you could:

if let json = NSJSONSerialization.JSONObjectWithData(data, options: nil, error: &error) as? NSArray, let dictionary = json.firstObject as? NSDictionary {
    println(dictionary)
} else {
    println(error)
}

Or you could cast it as an array of dictionaries:

if let json = NSJSONSerialization.JSONObjectWithData(data, options: nil, error: &error) as? [[String: AnyObject]], let dictionary = json.first {
    println(dictionary)
} else {
    println(error)
}