Swift: Can't seem to access objects in nested array - swift3

Question

I am testing my feet in Swift and am trying to access certain objects which are part of a nested array.
The structure of the array looks something like this:
[ "Title": "Book Title", "Type": "Fiction", "Chapters": [
{"Title": "Chapter 1 Title", "Content": "Lorem ipsum dolor sit amet...", "Keyword": "foo"},
{"Title": "Chapter 3 Title", "Content": "Lorem ipsum dolor sit amet...", "Keyword": "foo"},
{"Title": "Chapter 5 Title", "Content": "Lorem ipsum dolor sit amet...", "Keyword": "foo"},
...
],
[ "Title": "Book Title", "Type": "Fiction", "Chapters": [
{"Title": "Chapter 2 Title", "Content": "Lorem ipsum dolor sit amet...", "Keyword": "foo"},
{"Title": "Chapter 3 Title", "Content": "Lorem ipsum dolor sit amet...", "Keyword": "foo"}
],
...]
The array is loaded from a plist file and is loaded something like this:
var myArr: Array<Any>
myArr = NSArray(contentsOfFile: path!) as! [Dictionary<String, Any>]
I am having difficulty accessing specific children of the chapters array.
let bookNum = 1
let chapNum = 3
let s: Dictionary = myArr[bookNum] as! Dictionary<String, Any>
if let s1 = (s["Chapters"] as AnyObject)[chapNum] {
if let obj = s1 as! Dictionary<String, Any> {
print("/(obj["Title"])")
}
}
I get the error, that "Initializer for conditional binding must have optional type, not Dictionary".
In general I am getting the feeling that I am not doing this correctly. The problem is, that the exact structure of the array is not known. Theoretically a Book could be listed without chapters.
Thanks for help in advance.

Answer 1

You have already specified the myArr type as [Dictionary<String, Any>], so there is no need to explicitly specify the type of s because if you access object from myArr it should only dictionary nothing else.
let s = myArr[bookNum]
Now Chapters is also Array of dictionary so you need to type cast it that and then access the chapter according to you want.
if let chapters = s["Chapters"] as? [Dictionary<String, Any>] {// OR [[String:Any]]
if chapNum < chapters.count {
print(chapters[chapNum]["Title"])
}
}