Swift Codable with reserved word

Question

I have a situation where the JSON being returned from an API has a field named extension, which is a reserved word in Swift. My codable is blowing up when I try to use it.

I've searched for the last two hours, but I can't seem to find any solution.

Has anyone run into this before:

public struct PhoneNumber: Codable {

    var phoneNumber: String
    var extension: String
    var isPrimary: Bool
    var usageType: Int
}

Keyword 'extension' cannot be used as an identifier here

You can use backticks as shown in this [answer](https://stackoverflow.com/a/41504472/4056108) — chirag90, Jul 05 '18 at 13:18
You are most welcome @Bryan You should mark one of the answer below which worked for you. — chirag90, Jul 06 '18 at 07:01
Possible duplicate of [Swift variable name with \` (backtick)](https://stackoverflow.com/questions/41503740/swift-variable-name-with-backtick) — pkamb, Sep 28 '21 at 03:16

score 17 · Answer 1 · answered Jul 05 '18 at 13:19

17

Just add backticks to the variable name to make the compiler think that it's a variable, not a keyword.

var `extension`: String

answered Jul 05 '18 at 13:19

Papershine

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score 12 · Accepted Answer · answered Jul 05 '18 at 13:19

I've had similar problems with 'return'. You can get around with CodingKeys.

public struct PhoneNumber: Codable {
    enum CodingKeys: String, CodingKey {
        case phoneNumber
        case extensionString = "extension"
        case isPrimary
        case usageType
    }

  var phoneNumber: String
  var extensionString: String
  var isPrimiry: Bool
  var usageType: Int
}

As you cant call a property 'extension' you name it something similar but use the CodingKeys to tell you object what the key in the JSON is.

@Bryan this would be a better way than backticks – chirag90 Jul 05 '18 at 13:20 — chirag90, Jul 05 '18 at 13:20

Swift Codable with reserved word

2 Answers2