Deserialize JSON / NSDictionary to Swift objects

SWIFT 4 Update

Since you give a very simple JSON object the code prepared for to handle that model. If you need more complicated JSON models you need to improve this sample.

Your Custom Object

class Person : NSObject {
    var name : String = ""
    var email : String = ""
    var password : String = ""

    init(JSONString: String) {
        super.init()

        var error : NSError?
        let JSONData = JSONString.dataUsingEncoding(NSUTF8StringEncoding, allowLossyConversion: false)

        let JSONDictionary: Dictionary = NSJSONSerialization.JSONObjectWithData(JSONData, options: nil, error: &error) as NSDictionary

        // Loop
        for (key, value) in JSONDictionary {
            let keyName = key as String
            let keyValue: String = value as String

            // If property exists
            if (self.respondsToSelector(NSSelectorFromString(keyName))) {
                self.setValue(keyValue, forKey: keyName)
            }
        }
        // Or you can do it with using 
        // self.setValuesForKeysWithDictionary(JSONDictionary)
        // instead of loop method above
    }
}

And this is how you invoke your custom class with JSON string.

override func viewDidLoad() {
    super.viewDidLoad()
    let jsonString = "{ \"name\":\"myUser\", \"email\":\"user@example.com\", \"password\":\"passwordHash\" }"
    var aPerson : Person = Person(JSONString: jsonString)
    println(aPerson.name) // Output is "myUser"
}