CodingKeys non-decodable error

struct Item: Codable {
    let itemName: String
    let itemPrice: Int
    
    private enum CodingKeys: String, CodingKey {
        case itemName = "ItemName"
    }
}

In this case, an error will occur because only itemName is defined in the case of CodingKeys. So adding one case will eliminate the error.

struct Item: Codable {
    let itemName: String
    let itemPrice: Int
    
    private enum CodingKeys: String, CodingKey {
        case itemName = "ItemName"
        case itemPrice = "ItemPrice"
    }
}