How to insert Array inside a Dicionary in Swift

Question

I'm creating a drawing application in Swift that can be redrawn on canvas for HTML. Just a prototype. What I need is to get this data in JSON format to my database. I organized everything in arrays and dictionaries.

How can I generate something like this:

 {
  "data": [

  {

     "width": 150,

     "height": 200,

     "x": 45,

     "y": 65,

     "id": "line4"

  },

  {

     "width": 150,

     "height": 200,

     "x": 45,

     "y": 65,

     "id": "Shape1"

  },

  {

     "width": 150,

     "height": 200,

     "x": 45,

     "y": 65,

     "id": "line3"

  },

  {

     "width": 350,

     "height": 400,

     "x": 45,

     "y": 65,

     "id": "line2"

  }

  ]

  }

Using Arrays and Dicionaries (and / or Structs) and then turn into Json.

I tried to create a one Dictionary within an array within another Dictionary. The data is dynamic, that is the big problem.

help will be appreciated

So... your question is how to represent JSON structure in statically typed Swift? — GingerPlusPlus, Nov 27 '15 at 07:44

user3441734 · Accepted Answer · 2015-11-27T08:54:53.247

var arr: Array<Any> = []
var dict1: Dictionary<String,Any> = [:]
var dict: Dictionary<String,Any> = [:]

arr = ["text",1,true]
dict1["arr"] = arr
dict["dict1"] = dict1

// 

var dict2: Dictionary<String,Any> = [:]
dict["dict2"] = dict2

print(dict) // ["dict2": [:], "dict1": ["arr": ["text", 1, true]]]

withUnsafeMutablePointer(&dict["dict2"]) { (pdict2) -> Void in
    var pd = UnsafeMutablePointer<Dictionary<String,Any>>(pdict2)
    pd.memory.updateValue(arr, forKey: "arr2")
}

print(dict) // ["dict2": ["arr2": ["text", 1, true]], "dict1": ["arr": ["text", 1, true]]]

you can do it. i don't recommend you this approach. you are better to redesign you idea

score 0 · Answer 2 · edited May 23 '17 at 11:45

0

Here it says how to do it in Objective-C. You can port this solution to Swift.

Generate JSON string from NSDictionary in iOS

edited May 23 '17 at 11:45

Community

1
1

answered Nov 27 '15 at 07:50

BR41N-FCK

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The problem is Insert Dictionary in Array, inside another Dictionary. But tanks for your answer. – James Nov 27 '15 at 07:53
Do you need swift code? `var arr: [[key:value]]; // your array` `var dict1:[key:value] // your dictionary` `arr.append(dict1) // insert dictionary in the array` `var dict2:[key : [[key:value]]] //this dictionary will store your array` `dict2[key] = arr` – BR41N-FCK Nov 27 '15 at 08:01

score 0 · Answer 3 · answered Nov 27 '15 at 08:00

Not sure if that was your question but to create static structure all you have to do is to replace your curly braces with square brackets.

let data = [ "data": [
    [

        "width": 150,

        "height": 200,

        "x": 45,

        "y": 65,

        "id": "line4"

    ],
    [

        "width": 150,

        "height": 200,

        "x": 45,

        "y": 65,

        "id": "line1"

    ]
]
]

And to serialize it to JSON data:

let jsonData = try! NSJSONSerialization.dataWithJSONObject(data, options: NSJSONWritingOptions.PrettyPrinted)

And to deserialize back to Swift objects:

let data2 = try! NSJSONSerialization.JSONObjectWithData(jsonData, options: NSJSONReadingOptions.AllowFragments)

You might also want to create JSON string from the data:

let jsonString = String(data: jsonData, encoding: NSUTF8StringEncoding)

Or get data from JSON string:

let dataFromString = jsonString?.dataUsingEncoding(NSUTF8StringEncoding)

Of course you can then convert it to Swift objects using NSJSONSerialization.

Good answer, but still not exactly what I need. The 'data' must be supplied dynamically (for a function or something). — James, Nov 27 '15 at 08:02
What do you mean by "supplied dynamically"? To get exact answers you should specify exactly what you need. — Adam, Nov 27 '15 at 08:04

How to insert Array inside a Dicionary in Swift

3 Answers3