How to parse json response swift3?

Question

My response looks like this:

[
    {
        "Part" : {
            "id" : "418502",
            "uuid" : "21ec7cdb-cd2d-4b12-8a90-775762eb0f26"
        },
        "Category" : {
            "category_name" : "Regulators",
            "category_code" : "RG"
        }
    },
    {
        "Part" : {
             "id" : "418502",
             "uuid" : "21ec7cdb-cd2d-4b12-8a90-775762eb0f26"
        },
        "Category" : {
             "category_name" : "Regulators",
             "category_code" : "RG"
        }
    }
]

So I need to parse the above response to get Part array and Category array. After searching in google I found:

let resultJson = try JSONSerialization.jsonObject(with: data, options: []) as? [String : AnyObject]
print(resultJson!)

But it throws fatal error: unexpectedly found nil while unwrapping an Optional value.

I'm new to swift I don't know how to convert it. I have completed this in Android so I can surely say I get above response from server. I write a common function for calling web service, it works for other services so I think there is no problem in that.

How can I parse my response so I can get Part array and Category array? Thank you.

https://stackoverflow.com/questions/41734982/parsing-nested-array-of-dictionaries-using-object-mapper/41735194#41735194 — Umair Afzal, Jul 06 '17 at 04:44
Possible duplicate of [Correctly Parsing JSON in Swift 3](https://stackoverflow.com/questions/39423367/correctly-parsing-json-in-swift-3) — vadian, Jul 07 '17 at 04:00

Fangming · Accepted Answer · 2017-07-05T14:58:23.963

2

Your JSON structure has a top level array, so you cannot parse is as a dictionary. Try to do this

let resultJson = try JSONSerialization.jsonObject(with: data, options: []) as? [Any]
dump(resultJson!)

Sample code will be something like this. Don't forget to handle unwrap stuff

let str = "[{\"Part\":{\"id\":\"418502\",\"uuid\":\"21ec7cdb-cd2d-4b12-8a90-775762eb0f26\"},\"Category\":{\"category_name\":\"Regulators\",\"category_code\":\"RG\"}},{\"Part\":{\"id\":\"418502\",\"uuid\":\"21ec7cdb-cd2d-4b12-8a90-775762eb0f26\"},\"Category\":{\"category_name\":\"Regulators\",\"category_code\":\"RG\"}}]"

let data = str.data(using: .utf8)

do{
    let json = try JSONSerialization.jsonObject(with: data!, options: .mutableContainers) as? [Any]
    let dicInFirstElement = json?[0] as? [String: Any]
    let part = dicInFirstElement?["Part"]
    dump(part)
    //Pass this json into the following function
}catch let error{

}

edited Jul 05 '17 at 14:58

answered Jul 05 '17 at 14:29

Fangming

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@e.k Updated my answer. Your JSON is not correctly formatted. Correct it and let me know so that I can give you code to parse your JSON – Fangming Jul 05 '17 at 14:35
My response in very big I just put a small part from it – e.k Jul 05 '17 at 14:47
@e.k Updated my answer – Fangming Jul 05 '17 at 14:58
Yeah thank you very much. It helped now I can able to get arrays. – e.k Jul 05 '17 at 15:01

How to parse json response swift3?

1 Answers1