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iOS Parsing JSON Using Codable An Overview of Codable The Encodable Protocol

Posted by jakubhirner
jakubhirner
14,784 Points

Why does the size of JSON change?

import Foundation

let json = """
{
    "name": "Pasan",
    "id": 1,
    "role": "Teacher"
}
""".data(using: .utf8)! // this is 59 bytes

struct Employee: Codable {
    let name: String
    let id: Int
    let role: String

    enum CodingsKeys: String, CodingKey {
        case name = "name"
        case id = "id"
        case role = "role"
    }

    init(form decoder: Decoder) throws {
        let container = try decoder.container(keyedBy: CodingKeys.self)
        self.name = try container.decode(String.self, forKey: .name)
        self.id = try container.decode(Int.self, forKey: .id)
        self.role = try container.decode(String.self, forKey: .role)
    }
}

let decoder = JSONDecoder()
let employee = try! decoder.decode(Employee.self, from: json)

let encoder = JSONEncoder()
let encodedEmployee = try! encoder.encode(employee) // this is 40 bytes

But when we decode it do employee and then back to JSON the size decreases to 40 but not back to 59 why is this?

1 Answer

Chris Stromberg
PLUS
Chris Stromberg
Courses Plus Student 13,389 Points
Chris Stromberg
Chris Stromberg
Courses Plus Student 13,389 Points

You have a lot of whitespace around your initial JSON object.

let json = """
{"name":"Pasan","id":1,"role":"Teacher"}
""".data(using: .utf8)! // this is 40 bytes
jakubhirner
jakubhirner
14,784 Points

Thanks!