Codable with Key decoding strategy

Codable+KeyDecodingStrategy.swift

import UIKit

struct Country: Codable {
    let name: String
    let capital: String
    let callingCodes: [String]
}

let jsonData: Data = """
{
    "name": "United States of America",
    "capital": "Washington, D.C.",
    "calling_codes": ["1"]
}
""".data(using: .utf8)!

let decoder = JSONDecoder()

// To convert from `snake-case` JSON key to `camelCase` parameter name
decoder.keyDecodingStrategy = .convertFromSnakeCase

let country = try! decoder.decode(Country.self, from: jsonData)

print("Country calling codes = \(country.callingCodes.description)")