How to remove properties (key:values) from JSON object in Swift

Question

I have JSON that looks like:

[
    {
        WWW: "2",
        XXX: "2",
        YYY: "3",
        ZZZ: "4"
    },
    {
        WWW: "2",
        XXX: "5",
        YYY: "6",
        ZZZ: "7"
    },
    {
        WWW: "2",
        XXX: "2",
        YYY: "2",
        ZZZ: "3"
    }
]

But I'm only interested in working with and Y and Z.

Howe can I remove the entire W and X columns either from the raw JSON or from the JSON in the form of an Array in SWIFT?

Only answers I can find such as here seem outdated. Thanks for suggestions.

Decode the JSON with `JSONDecoder`(one of the top `swift` questions here on SO) and specify the CodingKeys you want to work with. — vadian, Jul 11 '20 at 19:05

Frankenstein · Accepted Answer · 2020-07-11T19:23:18.233

2

Use:

dict["WWW"] = nil
dict["XXX"] = nil

or:

dict.removeValue(forKey: "WWW")
dict.removeValue(forKey: "XXX")

Better Approach would be using JSONEncoder and CodingKeys.

struct Model: Decodable {
    var yyy, zzz: String

    enum CodingKeys: String, CodingKey {
        case yyy = "YYY", zzz = "ZZZ"
    }
}

edited Jul 11 '20 at 19:23

answered Jul 11 '20 at 19:04

Frankenstein

15,732
4
22
47

score 2 · Answer 2 · answered Jul 11 '20 at 19:13

Define your struct to match what you want, and then decode it:

struct Value: Decodable {
    enum CodingKeys: String, CodingKey {
        case y = "YYY"
        case z = "ZZZ"
    }
    var y: String
    var z: String
}

let value = try JSONDecoder().decode([Value].self, from: json)

This will exclude any keys you don't include.

How to remove properties (key:values) from JSON object in Swift

2 Answers2