nest parsing doesnt work

Hi


i did some searches in the internet but i doesnt found an usefull sample code where my json anser will parsed. i found on apple an similar answer in json and then i adapt it. but the code seems not to work...

xcode doesnt give me an usefull error if i run it...


here is my code:

//
//  ViewController.swift
//  test-api-calls
//
//  Copyright © 2017 Producer. All rights reserved.
//

import UIKit
import Foundation


struct CurrencyStore {
    var name: String
    var currencies: [Currency]

    struct Currency: Codable{
        var symbol1: String
        var maxPrice: Float
        var minPrice: Float
    }
}

let jsonvar = """
{"e":"currency_limits","ok":"ok","data":{"pairs":[{"symbol1":"BTC","symbol2":"USD","minLotSize":0.01,"minLotSizeS2":2.5,"maxLotSize":30,"minPrice":"100","maxPrice":"35000"},{"symbol1":"ETH","symbol2":"USD","minLotSize":0.1,"minLotSizeS2":2.5,"maxLotSize":1000,"minPrice":"2.5","maxPrice":"1024"},{"symbol1":"BCH","symbol2":"USD","minLotSize":0.01,"minLotSizeS2":2.5,"maxLotSize":30,"minPrice":"50","maxPrice":"5128"},{"symbol1":"BTG","symbol2":"USD","minLotSize":0.01,"minLotSizeS2":2.5,"maxLotSize":null,"minPrice":"2.5","maxPrice":"2048"},{"symbol1":"DASH","symbol2":"USD","minLotSize":0.01,"minLotSizeS2":2.5,"maxLotSize":null,"minPrice":"2.5","maxPrice":"1024"},{"symbol1":"XRP","symbol2":"USD","minLotSize":10,"minLotSizeS2":2.5,"maxLotSize":null,"minPrice":"0.005","maxPrice":"50"},{"symbol1":"ZEC","symbol2":"USD","minLotSize":0.01,"minLotSizeS2":2.5,"maxLotSize":null,"minPrice":"2.5","maxPrice":"1024"},{"symbol1":"BTC","symbol2":"EUR","minLotSize":0.01,"minLotSizeS2":2.2,"maxLotSize":30,"minPrice":"100.00","maxPrice":"35000"},{"symbol1":"ETH","symbol2":"EUR","minLotSize":0.1,"minLotSizeS2":2.2,"maxLotSize":null,"minPrice":"2","maxPrice":"1024"},{"symbol1":"BCH","symbol2":"EUR","minLotSize":0.01,"minLotSizeS2":2.5,"maxLotSize":null,"minPrice":"50","maxPrice":"5128"},{"symbol1":"BTG","symbol2":"EUR","minLotSize":0.01,"minLotSizeS2":2.5,"maxLotSize":null,"minPrice":"2.5","maxPrice":"2048"},{"symbol1":"DASH","symbol2":"EUR","minLotSize":0.01,"minLotSizeS2":2.5,"maxLotSize":null,"minPrice":"2.5","maxPrice":"1024"},{"symbol1":"XRP","symbol2":"EUR","minLotSize":10,"minLotSizeS2":2.5,"maxLotSize":null,"minPrice":"0.005","maxPrice":"50"},{"symbol1":"ZEC","symbol2":"EUR","minLotSize":0.01,"minLotSizeS2":2.5,"maxLotSize":null,"minPrice":"2.5","maxPrice":"1024"},{"symbol1":"BTC","symbol2":"GBP","minLotSize":0.01,"minLotSizeS2":2.2,"maxLotSize":null,"minPrice":"100","maxPrice":"30000"},{"symbol1":"ETH","symbol2":"GBP","minLotSize":0.1,"minLotSizeS2":2.2,"maxLotSize":null,"minPrice":"50","maxPrice":"5128"},{"symbol1":"BCH","symbol2":"GBP","minLotSize":0.01,"minLotSizeS2":2.5,"maxLotSize":null,"minPrice":"50","maxPrice":"4096"},{"symbol1":"DASH","symbol2":"GBP","minLotSize":0.01,"minLotSizeS2":2.2,"maxLotSize":null,"minPrice":"2.5","maxPrice":"1024"},{"symbol1":"ZEC","symbol2":"GBP","minLotSize":0.01,"minLotSizeS2":2.2,"maxLotSize":null,"minPrice":"2.5","maxPrice":"1024"},{"symbol1":"BTC","symbol2":"RUB","minLotSize":0.01,"minLotSizeS2":150,"maxLotSize":null,"minPrice":"10000","maxPrice":"2000000"},{"symbol1":"ETH","symbol2":"BTC","minLotSize":0.1,"minLotSizeS2":0.01,"maxLotSize":1000,"minPrice":"0.001","maxPrice":"2"},{"symbol1":"BCH","symbol2":"BTC","minLotSize":0.1,"minLotSizeS2":0.01,"maxLotSize":30,"minPrice":"0.005","maxPrice":"2"},{"symbol1":"BTG","symbol2":"BTC","minLotSize":0.01,"minLotSizeS2":0.001,"maxLotSize":null,"minPrice":"0.005","maxPrice":"2"},{"symbol1":"DASH","symbol2":"BTC","minLotSize":0.01,"minLotSizeS2":0.001,"maxLotSize":null,"minPrice":"0.005","maxPrice":"2"},{"symbol1":"XRP","symbol2":"BTC","minLotSize":40,"minLotSizeS2":0.001,"maxLotSize":null,"minPrice":"0.000003","maxPrice":"0.0005"},{"symbol1":"ZEC","symbol2":"BTC","minLotSize":0.01,"minLotSizeS2":0.001,"maxLotSize":null,"minPrice":"0.005","maxPrice":"2"},{"symbol1":"GHS","symbol2":"BTC","minLotSize":1,"minLotSizeS2":0.01,"maxLotSize":null,"minPrice":"0.00001","maxPrice":"0.01"}]}}
""".data(using: .utf8)!

struct CurrencyStoreService: Decodable {

    let e: String
    let ok: String
    let data: [data]

    struct data: Decodable {
        let pairs: [pairs]
     
        struct pairs: Decodable {
            let pairs: CurrencyStore.Currency
        }
    }
}

extension CurrencyStore {
    init(from CurrencyStoreService: CurrencyStoreService) {
        name = "Test"
        currencies = []
     
        for data in CurrencyStoreService.data {
            for pairs in data.pairs {
                currencies.append(pairs.pairs)
            }
        }
    }
}


class ViewController: UIViewController {

    override func viewDidLoad() {
        super.viewDidLoad()
     
        let decoder = JSONDecoder()
        let serviceStores = try decoder.decode([CurrencyStoreService].self, from: jsonvar)
     
        let stores = serviceStores.map { CurrencyStore (from: $0) }
     
        for store in stores {
            for Currency in store.currencies {
                print("\(Currency.symbol1) for max \(Currency.maxPrice) or at min \(Currency.minPrice)")
            }
        }

    }

     
    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }

}


probably someone has an sipmler way to parse it?

i get the template from here:

https://developer.apple.com/documentation/foundation/archives_and_serialization/using_json_with_custom_types


i dont implement an requst from the internet to make it simpler...

hopefully some one can help me...

feel free to change the complete code...

Up vote post of Quei Down vote post of Quei
2.5k views
Posted by
Quei
Reply
Add a Comment

Accepted Reply

There’s a number of problems with the code you posted. To investigate I first commented out line 23. This cuts out all of the parsing of 

Currency
values, so things should just work because it’s only parsing 
e
and 
ok
. Alas, it did not. The problem was line 49, where you’re passing in 
[CurrencyStoreService].self
rather than 
CurrencyStoreService.self
. The root of this JSON is a dictionary that maps to your 
CurrencyStoreService
type, not an array of such dictionaries.

With that out of the way I returned to 

data
. To help me understand your JSON better I reflowed it, and eliminated all but a few of the entries in the 
pairs
array: 
{
    "e": "currency_limits",
    "ok":"ok",
    "data":{
        "pairs":[
            {
                "symbol1":"BTC",
                "symbol2":"USD",
                "minLotSize":0.01,
                "minLotSizeS2":2.5,
                "maxLotSize":30,
                "minPrice":"100",
                "maxPrice":"35000"
            },
            {
                "symbol1":"ETH",
                "symbol2":"USD",
                "minLotSize":0.1,
                "minLotSizeS2":2.5,
                "maxLotSize":1000,
                "minPrice":"2.5",
                "maxPrice":"1024"
            },
            {
                "symbol1":"BCH",
                "symbol2":"USD",
                "minLotSize":0.01,
                "minLotSizeS2":2.5,
                "maxLotSize":30,
                "minPrice":"50",
                "maxPrice":"5128"
            },
        ]
    }
}

This makes it easy to see that 

data
isn’t an array, it’s a single item with a property 
pairs
that’s an array. I tweaked your model as follows: 
struct CurrencyStoreService: Decodable {

    let e: String
    let ok: String
    let data: NestedData

    struct NestedData: Decodable {
        let pairs: [CurrencyStore.Currency]
    }
}

and now things decode properly.

Share and Enjoy
—
Quinn “The Eskimo!”
Apple Developer Relations, Developer Technical Support, Core OS/Hardware 

let myEmail = "eskimo" + "1" + "@apple.com"
Posted by
eskimo
Up vote reply of eskimo Down vote reply of eskimo
Post marked as solved
Add a Comment

Replies

— The maxPrice and minPrice values in your JSON source are strings, not numbers. In your CurrencyStore.Currency struct, they're numbers, not strings.


— If JSONDecoder parsing fails, it throws an error. To see what the error is, catch the error and print it.

Posted by
QuinceyMorris
Post not yet marked as solved Up vote reply of QuinceyMorris Down vote reply of QuinceyMorris
Add a Comment

Thanks you are right!

Some nummbers are stings...

i have now adapt it:


import Foundation


struct CurrencyStore {
    var name: String
    var currencies: [Currency]

    struct Currency: Codable{
        var symbol1: String
        var maxPrice: String
        var minPrice: String
    }
}

let json = """
{"e":"currency_limits","ok":"ok","data":{"pairs":[{"symbol1":"BTC","symbol2":"USD","minLotSize":0.01,"minLotSizeS2":2.5,"maxLotSize":30,"minPrice":"100","maxPrice":"35000"},{"symbol1":"ETH","symbol2":"USD","minLotSize":0.1,"minLotSizeS2":2.5,"maxLotSize":1000,"minPrice":"2.5","maxPrice":"1024"},{"symbol1":"BCH","symbol2":"USD","minLotSize":0.01,"minLotSizeS2":2.5,"maxLotSize":30,"minPrice":"50","maxPrice":"5128"},{"symbol1":"BTG","symbol2":"USD","minLotSize":0.01,"minLotSizeS2":2.5,"maxLotSize":null,"minPrice":"2.5","maxPrice":"2048"},{"symbol1":"DASH","symbol2":"USD","minLotSize":0.01,"minLotSizeS2":2.5,"maxLotSize":null,"minPrice":"2.5","maxPrice":"1024"},{"symbol1":"XRP","symbol2":"USD","minLotSize":10,"minLotSizeS2":2.5,"maxLotSize":null,"minPrice":"0.005","maxPrice":"50"},{"symbol1":"ZEC","symbol2":"USD","minLotSize":0.01,"minLotSizeS2":2.5,"maxLotSize":null,"minPrice":"2.5","maxPrice":"1024"},{"symbol1":"BTC","symbol2":"EUR","minLotSize":0.01,"minLotSizeS2":2.2,"maxLotSize":30,"minPrice":"100.00","maxPrice":"35000"},{"symbol1":"ETH","symbol2":"EUR","minLotSize":0.1,"minLotSizeS2":2.2,"maxLotSize":null,"minPrice":"2","maxPrice":"1024"},{"symbol1":"BCH","symbol2":"EUR","minLotSize":0.01,"minLotSizeS2":2.5,"maxLotSize":null,"minPrice":"50","maxPrice":"5128"},{"symbol1":"BTG","symbol2":"EUR","minLotSize":0.01,"minLotSizeS2":2.5,"maxLotSize":null,"minPrice":"2.5","maxPrice":"2048"},{"symbol1":"DASH","symbol2":"EUR","minLotSize":0.01,"minLotSizeS2":2.5,"maxLotSize":null,"minPrice":"2.5","maxPrice":"1024"},{"symbol1":"XRP","symbol2":"EUR","minLotSize":10,"minLotSizeS2":2.5,"maxLotSize":null,"minPrice":"0.005","maxPrice":"50"},{"symbol1":"ZEC","symbol2":"EUR","minLotSize":0.01,"minLotSizeS2":2.5,"maxLotSize":null,"minPrice":"2.5","maxPrice":"1024"},{"symbol1":"BTC","symbol2":"GBP","minLotSize":0.01,"minLotSizeS2":2.2,"maxLotSize":null,"minPrice":"100","maxPrice":"30000"},{"symbol1":"ETH","symbol2":"GBP","minLotSize":0.1,"minLotSizeS2":2.2,"maxLotSize":null,"minPrice":"50","maxPrice":"5128"},{"symbol1":"BCH","symbol2":"GBP","minLotSize":0.01,"minLotSizeS2":2.5,"maxLotSize":null,"minPrice":"50","maxPrice":"4096"},{"symbol1":"DASH","symbol2":"GBP","minLotSize":0.01,"minLotSizeS2":2.2,"maxLotSize":null,"minPrice":"2.5","maxPrice":"1024"},{"symbol1":"ZEC","symbol2":"GBP","minLotSize":0.01,"minLotSizeS2":2.2,"maxLotSize":null,"minPrice":"2.5","maxPrice":"1024"},{"symbol1":"BTC","symbol2":"RUB","minLotSize":0.01,"minLotSizeS2":150,"maxLotSize":null,"minPrice":"10000","maxPrice":"2000000"},{"symbol1":"ETH","symbol2":"BTC","minLotSize":0.1,"minLotSizeS2":0.01,"maxLotSize":1000,"minPrice":"0.001","maxPrice":"2"},{"symbol1":"BCH","symbol2":"BTC","minLotSize":0.1,"minLotSizeS2":0.01,"maxLotSize":30,"minPrice":"0.005","maxPrice":"2"},{"symbol1":"BTG","symbol2":"BTC","minLotSize":0.01,"minLotSizeS2":0.001,"maxLotSize":null,"minPrice":"0.005","maxPrice":"2"},{"symbol1":"DASH","symbol2":"BTC","minLotSize":0.01,"minLotSizeS2":0.001,"maxLotSize":null,"minPrice":"0.005","maxPrice":"2"},{"symbol1":"XRP","symbol2":"BTC","minLotSize":40,"minLotSizeS2":0.001,"maxLotSize":null,"minPrice":"0.000003","maxPrice":"0.0005"},{"symbol1":"ZEC","symbol2":"BTC","minLotSize":0.01,"minLotSizeS2":0.001,"maxLotSize":null,"minPrice":"0.005","maxPrice":"2"},{"symbol1":"GHS","symbol2":"BTC","minLotSize":1,"minLotSizeS2":0.01,"maxLotSize":null,"minPrice":"0.00001","maxPrice":"0.01"}]}}
""".data(using: .utf8)!

struct CurrencyStoreService: Decodable {

    let e: String
    let ok: String
    let data: [data]

    struct data: Decodable {
        let pairs: [pairs]
     
        struct pairs: Decodable {
            let pairs: CurrencyStore.Currency
        }
    }
}

extension CurrencyStore {
    init(from CurrencyStoreService: CurrencyStoreService) {
        name = CurrencyStoreService.ok
        currencies = []
     
        for data in CurrencyStoreService.data {
            for pairs in data.pairs {
                currencies.append(pairs.pairs)
            }
        }
    }
}

do {
    let decoder = JSONDecoder()
    let serviceStores = try decoder.decode([CurrencyStoreService].self, from: json)
    print(serviceStores)
    let stores = serviceStores.map { CurrencyStore (from: $0) }

    for store in stores {
        for Currency in store.currencies {
            print("\(Currency.symbol1) for max \(Currency.maxPrice) or at min \(Currency.minPrice)")
        }
    }

} catch let jsonErr {
    print(jsonErr)

}


so now i get an error.

typeMismatch(Swift.Array<Any>, Swift.DecodingError.Context(codingPath: [], debugDescription: "Expected to decode Array<Any> but found a dictionary instead.", underlyingError: nil))


why is it an dictionary and not an array?

Posted by
Quei
Up vote reply of Quei Down vote reply of Quei
Add a Comment

There’s a number of problems with the code you posted. To investigate I first commented out line 23. This cuts out all of the parsing of 

Currency
values, so things should just work because it’s only parsing 
e
and 
ok
. Alas, it did not. The problem was line 49, where you’re passing in 
[CurrencyStoreService].self
rather than 
CurrencyStoreService.self
. The root of this JSON is a dictionary that maps to your 
CurrencyStoreService
type, not an array of such dictionaries.

With that out of the way I returned to 

data
. To help me understand your JSON better I reflowed it, and eliminated all but a few of the entries in the 
pairs
array: 
{
    "e": "currency_limits",
    "ok":"ok",
    "data":{
        "pairs":[
            {
                "symbol1":"BTC",
                "symbol2":"USD",
                "minLotSize":0.01,
                "minLotSizeS2":2.5,
                "maxLotSize":30,
                "minPrice":"100",
                "maxPrice":"35000"
            },
            {
                "symbol1":"ETH",
                "symbol2":"USD",
                "minLotSize":0.1,
                "minLotSizeS2":2.5,
                "maxLotSize":1000,
                "minPrice":"2.5",
                "maxPrice":"1024"
            },
            {
                "symbol1":"BCH",
                "symbol2":"USD",
                "minLotSize":0.01,
                "minLotSizeS2":2.5,
                "maxLotSize":30,
                "minPrice":"50",
                "maxPrice":"5128"
            },
        ]
    }
}

This makes it easy to see that 

data
isn’t an array, it’s a single item with a property 
pairs
that’s an array. I tweaked your model as follows: 
struct CurrencyStoreService: Decodable {

    let e: String
    let ok: String
    let data: NestedData

    struct NestedData: Decodable {
        let pairs: [CurrencyStore.Currency]
    }
}

and now things decode properly.

Share and Enjoy
—
Quinn “The Eskimo!”
Apple Developer Relations, Developer Technical Support, Core OS/Hardware 

let myEmail = "eskimo" + "1" + "@apple.com"
Posted by
eskimo
Up vote reply of eskimo Down vote reply of eskimo
Post marked as solved
Add a Comment

Many thanks for your help!!!


Can you please post the complete code?

i didnt get it to work...

Sorry i am verry new in swift...

Posted by
Quei
Up vote reply of Quei Down vote reply of Quei
Add a Comment

Thanks Eskimo, i have implemented that now!


here is the code:


import Foundation


struct CurrencyStore {
    var name: String
    var currencies: [Currency]

    struct Currency: Codable{
        var symbol1: String
        var symbol2: String
        var minLotSize: Double
        var minLotSizeS2: Double
        var maxLotSize: Double?
        var maxPrice: String
        var minPrice: String
    }
}

let json = """
{"e":"currency_limits","ok":"ok","data":{"pairs":[{"symbol1":"BTC","symbol2":"USD","minLotSize":0.01,"minLotSizeS2":2.5,"maxLotSize":30,"minPrice":"100","maxPrice":"35000"},{"symbol1":"ETH","symbol2":"USD","minLotSize":0.1,"minLotSizeS2":2.5,"maxLotSize":1000,"minPrice":"2.5","maxPrice":"1024"},{"symbol1":"BCH","symbol2":"USD","minLotSize":0.01,"minLotSizeS2":2.5,"maxLotSize":30,"minPrice":"50","maxPrice":"5128"},{"symbol1":"BTG","symbol2":"USD","minLotSize":0.01,"minLotSizeS2":2.5,"maxLotSize":null,"minPrice":"2.5","maxPrice":"2048"},{"symbol1":"DASH","symbol2":"USD","minLotSize":0.01,"minLotSizeS2":2.5,"maxLotSize":null,"minPrice":"2.5","maxPrice":"1024"},{"symbol1":"XRP","symbol2":"USD","minLotSize":10,"minLotSizeS2":2.5,"maxLotSize":null,"minPrice":"0.005","maxPrice":"50"},{"symbol1":"ZEC","symbol2":"USD","minLotSize":0.01,"minLotSizeS2":2.5,"maxLotSize":null,"minPrice":"2.5","maxPrice":"1024"},{"symbol1":"BTC","symbol2":"EUR","minLotSize":0.01,"minLotSizeS2":2.2,"maxLotSize":30,"minPrice":"100.00","maxPrice":"35000"},{"symbol1":"ETH","symbol2":"EUR","minLotSize":0.1,"minLotSizeS2":2.2,"maxLotSize":null,"minPrice":"2","maxPrice":"1024"},{"symbol1":"BCH","symbol2":"EUR","minLotSize":0.01,"minLotSizeS2":2.5,"maxLotSize":null,"minPrice":"50","maxPrice":"5128"},{"symbol1":"BTG","symbol2":"EUR","minLotSize":0.01,"minLotSizeS2":2.5,"maxLotSize":null,"minPrice":"2.5","maxPrice":"2048"},{"symbol1":"DASH","symbol2":"EUR","minLotSize":0.01,"minLotSizeS2":2.5,"maxLotSize":null,"minPrice":"2.5","maxPrice":"1024"},{"symbol1":"XRP","symbol2":"EUR","minLotSize":10,"minLotSizeS2":2.5,"maxLotSize":null,"minPrice":"0.005","maxPrice":"50"},{"symbol1":"ZEC","symbol2":"EUR","minLotSize":0.01,"minLotSizeS2":2.5,"maxLotSize":null,"minPrice":"2.5","maxPrice":"1024"},{"symbol1":"BTC","symbol2":"GBP","minLotSize":0.01,"minLotSizeS2":2.2,"maxLotSize":null,"minPrice":"100","maxPrice":"30000"},{"symbol1":"ETH","symbol2":"GBP","minLotSize":0.1,"minLotSizeS2":2.2,"maxLotSize":null,"minPrice":"50","maxPrice":"5128"},{"symbol1":"BCH","symbol2":"GBP","minLotSize":0.01,"minLotSizeS2":2.5,"maxLotSize":null,"minPrice":"50","maxPrice":"4096"},{"symbol1":"DASH","symbol2":"GBP","minLotSize":0.01,"minLotSizeS2":2.2,"maxLotSize":null,"minPrice":"2.5","maxPrice":"1024"},{"symbol1":"ZEC","symbol2":"GBP","minLotSize":0.01,"minLotSizeS2":2.2,"maxLotSize":null,"minPrice":"2.5","maxPrice":"1024"},{"symbol1":"BTC","symbol2":"RUB","minLotSize":0.01,"minLotSizeS2":150,"maxLotSize":null,"minPrice":"10000","maxPrice":"2000000"},{"symbol1":"ETH","symbol2":"BTC","minLotSize":0.1,"minLotSizeS2":0.01,"maxLotSize":1000,"minPrice":"0.001","maxPrice":"2"},{"symbol1":"BCH","symbol2":"BTC","minLotSize":0.1,"minLotSizeS2":0.01,"maxLotSize":30,"minPrice":"0.005","maxPrice":"2"},{"symbol1":"BTG","symbol2":"BTC","minLotSize":0.01,"minLotSizeS2":0.001,"maxLotSize":null,"minPrice":"0.005","maxPrice":"2"},{"symbol1":"DASH","symbol2":"BTC","minLotSize":0.01,"minLotSizeS2":0.001,"maxLotSize":null,"minPrice":"0.005","maxPrice":"2"},{"symbol1":"XRP","symbol2":"BTC","minLotSize":40,"minLotSizeS2":0.001,"maxLotSize":null,"minPrice":"0.000003","maxPrice":"0.0005"},{"symbol1":"ZEC","symbol2":"BTC","minLotSize":0.01,"minLotSizeS2":0.001,"maxLotSize":null,"minPrice":"0.005","maxPrice":"2"},{"symbol1":"GHS","symbol2":"BTC","minLotSize":1,"minLotSizeS2":0.01,"maxLotSize":null,"minPrice":"0.00001","maxPrice":"0.01"}]}}
""".data(using: .utf8)!

struct CurrencyStoreService: Decodable {

    let e: String
    let ok: String
    let data: NestedData

    struct NestedData: Decodable {
        let pairs: [CurrencyStore.Currency]
    }
}

extension CurrencyStore {
    init(from CurrencyStoreService: CurrencyStoreService) {
        name = CurrencyStoreService.ok
        currencies = []
    }
}

do {
    let decoder = JSONDecoder()
    let serverData = try decoder.decode(CurrencyStoreService.self, from: json)
    print(serverData.data.pairs)

} catch let jsonErr {
    print(jsonErr)

}
Posted by
Quei
Up vote reply of Quei Down vote reply of Quei
Add a Comment