NSDictionary使用SwiftyJSON将JSON字符串转换为JSON对象

Question

I have a use case where I have an array of dictionaries and I need them as a json object:

var data = [Dictionary<String, String>]()
//append items 
var bytes = NSJSONSerialization.dataWithJSONObject(data, options: NSJSONWritingOptions.allZeros, error: nil)
var jsonObj = JSON(NSString(data: bytes!, encoding: NSUTF8StringEncoding)!)

println(jsonObj)
println(jsonObj[0])

The first print statement gives me

[
    {"price":"1.20","city":"Foo","_id":"326105","street":"One"},
    {"price":"1.20","city":"Bar","_id":"326104","street":"Two"}
]

the second

null

but I would expect it to return the first element in the json array. What I am doing wrong?

Answer 1

According to the docs, this should be all you need.

var data = [Dictionary<String, String>]()
//append items 
var jsonObj = JSON(data)

println(jsonObj)
println(jsonObj[0])

Are you having a problem with converting an array directly into a JSON object?

Answer 2

I'm not sure what method you have on the 4th line there (JSON) but I got your code to work using NSJSONSerialization.JSONObjectWithData seen below:

var data = [Dictionary<String, String>]()
data.append(["price":"1.20","city":"Foo","_id":"326105","street":"One"])
data.append(["price":"1.20","city":"Bar","_id":"326104","street":"Two"])

let bytes = try! NSJSONSerialization.dataWithJSONObject(data, options: NSJSONWritingOptions.PrettyPrinted)
var jsonObj = try! NSJSONSerialization.JSONObjectWithData(bytes, options: .MutableLeaves) as! [Dictionary<String, String>]

print(jsonObj)
print(jsonObj[0])

... with output ...

"[[price: 1.20, city: Foo, _id: 326105, street: One], [price: 1.20, city: Bar, _id: 326104, street: Two]]"

"[price: 1.20, city: Foo, _id: 326105, street: One]"

Edit: I see now the tag for swifty-json. I'm not familiar with that, but the code I included above works with the built in methods.