Swift 4-SwiftyJson比较数组并合并找到的值

Question

我有一个JSON对象，其中包含名称和值的列表。 我想与另一个数组[String]进行比较，如果在一个JSON对象值中找到该值，则将该值合并到一个新对象中。

我试过在for循环中使用merge(with) ，但是，似乎只是合并一个值。

 > 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

此代码使用Swift 4基础JSON解析器。 Swift 4默认具有奇迹解析器。

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)

Answer 2

您可以这样实现循环：

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

    }
})

合并功能实际上是用于合并数据。 像这个例子：

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"
//     ]
// ]