I have a pretty complex data structure in my app, which I need to manipulate. I am trying to keep track of how many types of bugs a player has in thier garden. There are te
I had the same issue, where I wanted to get boolValue nested in dictionary.
{
"Level1": {
"leve2": {
"code": 0,
"boolValue": 1
}
}
}
I tried a lot of solution but those didn't worked for me as i was missing type casting. So I used following code to get the boolValue from json, where json is a nested dictionary of type [String:Any].
let boolValue = ((json["level1"]
as? [String: Any])?["level2"]
as? [String: Any])?["boolValue"] as? Bool
My primary use case was reading ad-hoc values from a deep dictionary. None of the answers given worked for me in my Swift 3.1 project, so I went looking and found Ole Begemann's excellent extension for Swift dictionaries, with a detailed explanation on how it works.
I've made a Github gist with the Swift file I made for using it, and I welcome feedback.
To use it, you can add the Keypath.swift into your project, and then you can simply use a keyPath subscript syntax on any [String:Any]
dictionary as follows.
Considering you have a JSON object like so:
{
"name":"John",
"age":30,
"cars": {
"car1":"Ford",
"car2":"BMW",
"car3":"Fiat"
}
}
stored in a dictionary var dict:[String:Any]
. You could use the following syntax to get to the various depths of the object.
if let name = data[keyPath:"name"] as? String{
// name has "John"
}
if let age = data[keyPath:"age"] as? Int{
// age has 30
}
if let car1 = data[keyPath:"cars.car1"] as? String{
// car1 has "Ford"
}
Note that the extension supports writing into nested dictionaries as well, but I haven't yet used this.
I still haven't found a way to access arrays within dictionary objects using this, but it's a start! I'm looking for a JSON Pointer implementation for Swift but haven't found one, yet.
The Swift 4 default:
subscript for Dictionaries makes makes updating values in nested Dictionaries much more concise.
Get and Set a default value rather than dealing with optionals:
var dict = [String : [String : String]]()
dict["deep", default: [:]]["nested"] = "dictionary"
print(dict)
// ["deep": ["nested": "dictionary"]]
https://swift.org/blog/dictionary-and-set-improvements/
Another option: You could try calling dict.value( forKeyPath: "ladybug.spotted.red" )!
So I just tried this with Swift 5:
import Foundation
var d = [ "ladybug" : [ "spotted" : [ "red" : 123 ] ] ] as [String:Any]
(d as NSDictionary).value(forKeyPath: "ladybug.spotted.red")
and it works, but this is probably the best way:
d["ladybug"]?["spotted"]?["red"]