how to loop through an array of objects and create a json object?

Question

I have an array of 300 objects which each object contain many parameters and I want to loop through the array to create a JSON object which contain only two parameters. my objects were created from this json structure in the array :

 "publicationId": 13,
            "name": null,
            "code": "FIGA_20190516",
            "parutionDate": "2019-05-16",
            "quadri": "FIGA",
            "ratio": null,
            "numero": "0",
            "createdAt": "2019-06-18 21:29:21",
            "nbPages": 0,
            "search": 1,
            "down": 1,
            "thumb_height": 0,
            "quartPageWidth": 0,
            "quartPageHeight": 0,
            "pdfHeight": "0",
            "pdfWidth": "0",
            "PDF": "2019-06-18 21:29:21",
            "XML": null,
            "SendKM": "2019-06-18 21:29:21",
            "KM": null,
            "Melody": null,
            "filename": null,
            "SendNormalize": null,
            "Normalized": null,
            "librelioSubTitle": null,
            "SendProcessArticle": null,
            "ProcessedArticles": null,
            "melodyCallBackUrl": null,
            "htmlMilibris": false,
            "htmlHarry": false,
            "sendProcessLibrelio": null,
            "processedLibrelio": null,
            "id": 77066,
            "_solrDocument": {},
            "_repository": "FIGA/2019/05/FIGA_20190516/"

and I want to loop through the array to create a JSON object with this struct :

"availableParutions" : {
        id : createdAt,
        id : createdAt,
        id : createdAt
    }

I really appreciate your help guys !

Hi @mark, where did you get JSON data? Service or is it involved in the project? — emrcftci
– emrcftci, Commented Jun 27, 2019 at 14:03
Is it the same as: stackoverflow.com/questions/42081141/…? — Ahmad F
– Ahmad F, Commented Jun 27, 2019 at 14:08
hey @Ahmed nope it's not the same structure I can create a structure of array of objects [{obj},{obj},{obj}] like the exemple you posted but this is an other format {key:value, key:value, key:value} — mark
– mark, Commented Jun 27, 2019 at 14:12

Joakim Danielson · Accepted Answer · 2019-06-27 17:35:34Z

1

You can create a new struct that represents the data you want in your Json output

struct NewStruct: Encodable {
    let id: Int
    let createAt: String
}

This struct conforms to Encodable so that it can be encoded to json but since it is so simple no extra coding is needed

Then you can convert your array of large objects to an array of NewStruct using map

let newArray = array.map { NewStruct(id: $0.id, createAt: $0.createdAt) }

If I understand it correctly this array should be a property named "availableParutions" so lets make an outer struct for the json

struct Output: Codable {
    let availableParutions: [NewStruct]
}

and load it

let output = Output(availableParutions: newArray)

and encode it

do {
    let jsonData = try JSONEncoder().encode(output)
} catch {
    print(error)
}

answered Jun 27, 2019 at 17:35

Joakim Danielson

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1 Comment

mark Over a year ago

Thank you Joakim you saved me !

Bhavik Modi · Accepted Answer · 2019-06-27 14:11:01Z

1

You can try the following code:

Note: I have create json obj my self for evaluation purpose, you can use your json directly.

    let json = [
        [
        "publicationId":11,
        "createdAt":"2019-06-18 21:29:21",
        "id":77063,
        ],
        [
            "publicationId":12,
            "createdAt":"2019-06-18 21:29:21",
            "id":77065,
        ],
        [
            "publicationId":13,
            "createdAt":"2019-06-18 21:29:21",
            "id":77066,
        ]
        ]

 var jsonArr: [[String:Any]] = [[String:Any]]()
        for obj in json {
            let id = obj["id"] as! Int
            let jsonObj = [
                "\(id)": obj["createdAt"] as! String
            ]
            jsonArr.append(jsonObj as [String : Any])
        }
        print(jsonArr)

answered Jun 27, 2019 at 14:11

Bhavik Modi

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1 Comment

mark Over a year ago

Hey @Bhavik ! thank you for your reply, so first my array dosen't contain json it contain objects created from the passed json format, second I tested your code and it gives me this format:[["77063": "2019-06-18 21:29:21"], ["77065": "2019-06-18 21:29:21"], ["77066": "2019-06-18 21:29:21"]] and it don't match the format I want, thank you for your try

Johnykutty · Accepted Answer · 2019-06-27 14:37:35Z

0

You could create an empty dictionary, then iterate over json array and pull out id & createdAt. Update dictionary with id & createdAt. Finally set this dictionary as value of availableParutions in a new dictionary.

code:

    var map: [Int: Any]  = [:]
    for item in json {
        let id = item["id"] as! Int
        map[id] = item["createdAt"]!
    }
    let outerObject = ["availableParutions": map]
    print(outerObject)

answered Jun 27, 2019 at 14:37

Johnykutty

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