NSJSONSerialization.JSONObjectWithData Returns nil
[
{
"_id": "557f27522afb79ce0112e6ab",
"endereco": {
"cep": "asdasd",
"numero": "asdasd"
},
"categories": [],
"name": "teste",
"hashtag": "teste"
}
]
Returns zero with no errors:
var json = NSJSONSerialization.JSONObjectWithData(data, options:NSJSONReadingOptions.AllowFragments, error: &erro) as? NSDictionary
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It returns nil
without error because it is not JSON parsing which is failing. It doesn't work due to the conditional type of casting the resulting object as a dictionary. This JSON does not represent a dictionary: it is an array with one element (which turns out to be a dictionary). External [
and ]
indicate an array. So when you parse it, you want to use it like NSArray
.
For example, in Swift 1.2, you can:
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 can use it like 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)
}
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Calling isValidJSONObject: or attempting to convert are the final ways to determine if a given object can be converted to JSON data.
isValidJSONObject (_ :) Returns a Boolean value indicating whether this object can be converted to JSON data.
SWIFT declaration class func isValidJSONObject (_ obj: AnyObject) → Bool OBJ parameters Object for testing. Return value true if obj can be converted to JSON data; otherwise, false.
Discussion Availability Available in iOS 5.0 and later.
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