NSJSONSerialization to swift dictionary
I have a json object that I need to serialize into a dictionary. I know this can be serialized to NSDictionary, but since
"in Swift 1.2, Objective-C classes that have their own Swift equivalents (NSString, NSArray, NSDictionary, etc.) are no longer automatically concatenated."
Link: [ http://www.raywenderlich.com/95181/whats-new-in-swift-1-2]
I prefer it in the native swift dictionary to avoid the awkward bridge.
I cannot use NSJSONSerialization method as it only maps to NSDictionay. What's another way to serialize JSON into a swift dictionary?
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With a Swift dictionary you can use directly NSJSONSerialization
.
Example for {"id": 42}
:
let str = "{\"id\": 42}"
let data = str.dataUsingEncoding(NSUTF8StringEncoding)
let json = NSJSONSerialization.JSONObjectWithData(data!, options: NSJSONReadingOptions.MutableContainers, error: nil) as! [String:Int]
println(json["id"]!) // prints 42
Or with AnyObject
:
let json = NSJSONSerialization.JSONObjectWithData(data!, options: NSJSONReadingOptions.MutableContainers, error: nil) as! [String:AnyObject]
if let number = json["id"] as? Int {
println(number) // prints 42
}
UPDATE:
If your data might be null, you need to use a safe unwrap to avoid errors:
let str = "{\"id\": 42}"
if let data = str.dataUsingEncoding(NSUTF8StringEncoding) {
// With value as Int
if let json = NSJSONSerialization.JSONObjectWithData(data, options: NSJSONReadingOptions.MutableContainers, error: nil) as? [String:Int] {
if let id = json["id"] {
println(id) // prints 42
}
}
// With value as AnyObject
if let json = NSJSONSerialization.JSONObjectWithData(data, options: NSJSONReadingOptions.MutableContainers, error: nil) as? [String:AnyObject] {
if let number = json["id"] as? Int {
println(number) // prints 42
}
}
}
Update for Swift 2.0
do {
let str = "{\"id\": 42}"
if let data = str.dataUsingEncoding(NSUTF8StringEncoding) {
// With value as Int
if let json = try NSJSONSerialization.JSONObjectWithData(data, options: []) as? [String:Int] {
if let id = json["id"] {
print(id) // prints 42
}
}
// With value as AnyObject
if let json = try NSJSONSerialization.JSONObjectWithData(data, options: []) as? [String:AnyObject] {
if let number = json["id"] as? Int {
print(number) // prints 42
}
}
}
} catch {
print(error)
}
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