(Swift 3,4,5...) JSON: Nested Objects

Here we have a JSON object that contains nested JSON objects. This example demonstrates how to access the contents of the nested objects.

{
  "name": "donut",
  "image":
    {
    "fname": "donut.jpg",
    "w": 200,
    "h": 200
    },
  "thumbnail":
    {
    "fname": "donutThumb.jpg",
    "w": 32,
    "h": 32
    }
}

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func chilkatTest() {
    let json = CkoJsonObject()!

    // This is the above JSON with whitespace chars removed (SPACE, TAB, CR, and LF chars).
    // The presence of whitespace chars for pretty-printing makes no difference to the Load
    // method. 
    var jsonStr: String? = "{\"name\": \"donut\",\"image\":{\"fname\": \"donut.jpg\",\"w\": 200,\"h\": 200},\"thumbnail\":{\"fname\": \"donutThumb.jpg\",\"w\": 32,\"h\": 32}}"

    var success: Bool = json.load(jsonStr)
    if success != true {
        print("\(json.lastErrorText!)")
        return
    }

    // Get the "image" object.
    var imageObj: CkoJsonObject? = json.object(of: "image")
    if json.lastMethodSuccess == false {
        print("image object not found.")
        return
    }

    print("image: fname=\(imageObj!.string(of: "fname")!), width=\(imageObj!.int(of: "w").intValue), height=\(imageObj!.int(of: "h").intValue)")

    imageObj = nil

    // Get the "thumbnail" object.
    var thumbObj: CkoJsonObject? = json.object(of: "thumbnail")
    if json.lastMethodSuccess == false {
        print("thumbnail object not found.")
        return
    }

    print("thumbnail: fname=\(thumbObj!.string(of: "fname")!), width=\(thumbObj!.int(of: "w").intValue), height=\(thumbObj!.int(of: "h").intValue)")

    thumbObj = nil

}