Cannot convert Data to NSDictionary - json

Question

I'm trying to convert data from URLSession to a NSDictionary but it fails when converting the data to dictionary.
Following:
let json = try? JSONSerialization.jsonObject(with: data!, options: [])
print(json ?? "NotWorking")
outputs
(
{
babyId = 1;
id = 17;
timestamp = "2018-06-30 09:23:27";
}
)
But when I try to convert it into a Dictionary with following it outputs nil.
let json = try? JSONSerialization.jsonObject(with: data!, options: []) as? NSDictionary
The webpage outputs
[{"id":"17","babyId":"1","timestamp":"2018-06-30 09:23:27"}]
Where does the error occurs?

Answer 1

[ ] means array in JSON. { } means dictionary. You have an array of dictionary. Note that when you print an array in Swift, you will see ( ).
Don't use NSArray or NSDictionary in Swift without a very clearly understood and specific reason. Use a Swift array and dictionary of the proper types.
Your code should be:
do {
if let results = try JSONSerialization.jsonObject(with: data!) as? [[String:Any]] {
// results is now an array of dictionary, access what you need
} else {
print("JSON was not the expected array of dictonary")
}
} catch {
print("Can't process JSON: \(error)")
}
And really you shouldn't be using data! either. Somewhere above this you should have a if let data = data {