Swift 4 - SwiftyJson compare array and merge found values - ios

Question

I have a JSON object which contains a list of names and values. I want to compare to it another array [String] and if the value is found in one of the JSON object value merge that value to a new object.
I have tried using merge(with) in a for loop however, it seems to be merge just one value.
> example:
>
> json_cat =
>
> {
> name: "aaa",
> surname: "aaa-1",
> grade: "aaa-2"
> },
> {
> name: "bbb",
> surname: "bbb-1",
> grade: "bbb-2"
> },
> {
> name: "ccc",
> surname: "ccc-1",
> grade: "ccc-2"
> }
>
//
> let arraytest:[String] = ["aaa", "ccc", "ddd"]
>
// array json_cat compare arraytest
> result = {
> name: "aaa",
> surname: "aaa-1",
> grade: "aaa-2"
> },
> {
> name: "ccc",
> surname: "ccc-1",
> grade: "ccc-2"
> }
let json_cat: JSON = "json from url"
let arraytest:[String] = ["aaa", "ccc", "ddd"]
var json_cat_array = JSON()
json_cat.forEach({ (index, json_p) in
if arraytest.contains(json_p["name"].string!) {
//print("\(index) - \(json_p)")
try! json_cat_array.merge(with: json_p)
}
})

Answer 1

You could implement your loop like this:
json_cat.forEach({ (index, json_p) in
if arraytest.contains(json_p["name"].string!) {
//print("\(index) - \(json_p)")
json_cat_array[json_p["name"].string!] = json_p
}
})
The merge function is really for merging data. Like in this example:
let original: JSON = [
"first_name": "John",
"age": 20,
"skills": ["Coding", "Reading"],
"address": [
"street": "Front St",
"zip": "12345",
]
]
let update: JSON = [
"last_name": "Doe",
"age": 21,
"skills": ["Writing"],
"address": [
"zip": "12342",
"city": "New York City"
]
]
let updated = original.merge(with: update)
// [
// "first_name": "John",
// "last_name": "Doe",
// "age": 21,
// "skills": ["Coding", "Reading", "Writing"],
// "address": [
// "street": "Front St",
// "zip": "12342",
// "city": "New York City"
// ]
// ]

Answer 2

This code uses Swift 4 foundation JSON parser. Swift 4 has got wonder parser by default.
import Foundation
let jsonString = """
[{
"surname": "Roxxy",
"grade": "neaou"
},
{
"name": "Puffi",
"surname": "Chips",
"grade": "meaou"
},
{
"name": "Taffy",
"surname": "Baby",
"grade": "mew-mew"
}]
"""
struct JsonCat: Decodable {
let name: String?
let surname: String
let grade: String
}
struct Cat {
let name: String
let surname: String
let grade: String
}
guard let jsonData = jsonString.data(using: .utf8), let jsonCats = try? JSONDecoder().decode([JsonCat].self, from: jsonData) else {
fatalError()
}
var cats: [Cat] = []
jsonCats.forEach { jsonCat in
guard let name = jsonCat.name else {
return
}
let cat = Cat(name: name, surname: jsonCat.surname, grade: jsonCat.grade)
cats.append(cat)
}
print(cats)