Is it normal to have the data in the file written in a different order than it was programmed? – Swift – Hacking with Swift forums

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Is it normal to have the data in the file written in a different order than it was programmed?

	@blawson3 Jun '22 Currently I have an Array that is being used to hold student information, once the student info is entered the used presses "Save" which adds the info to the file in the documents directory. I have add a print statement that shows both the data and the directory path to the saved file. What I am trying to understand is why is the order of the information being entered is different than the order in the file being saved? I am using the JSON encoder/decoder. Any help is greatly appreciated. Thank you, Bob Here is the print of the data being saved: Roster = Student being saved to roster is Student(id: B0326D2C-FE9E-4F4C-BF3A-3A328EBCF6A6, firstName: "John", lastName: "Doe", birthdate: "8/25/86", emailAddress: "Jdoe@email.com", isIEP: false, is504: false, isELL: false, selectedPeriod: "secondPeriod", flexPeriod: true, active: true) Here is the print of the data in the file: {"active":true,"firstName":"John","id":"B0326D2C-FE9E-4F4C-BF3A-3A328EBCF6A6","emailAddress":"Jdoe@email.com","is504":false,"isIEP":false,"birthdate":"8\/25\/86","isELL":false,"selectedPeriod":"secondPeriod","flexPeriod":true,"lastName":"Doe"}] 2
	@Greenamberred HWS+ Jun '22 Check you structure for the data, you will find it is probably something like this `struct studentEntry: Codable { let active: Bool let firstName: String let id: String let emailAddress: String … }` So the encoding follows the struct definition. 2
	@blawson3 Jun '22 So here is my struct (that ends up inside my Class so it can be shared across the view as a single source). struct Student: Identifiable, Codable, Equatable, Hashable { let id: UUID let firstName: String let lastName: String let birthdate: String var emailAddress: String var isIEP: Bool var is504: Bool var isELL: Bool var selectedPeriod: String var flexPeriod: Bool var active: Bool } 2
	@blawson3 Jun '22 Here is the struct that I am using: `struct Student: Identifiable, Codable, Equatable, Hashable { let id: UUID let firstName: String let lastName: String let birthdate: String var emailAddress: String var isIEP: Bool var is504: Bool var isELL: Bool var selectedPeriod: String var flexPeriod: Bool var active: Bool }` 2
	@roosterboy HWS+ Jun '22 Any help is greatly appreciated. Help with what? There is nothing wrong. A struct (like your `Student`) is encoded into something called a `KeyedContainer`, which corresponds to a `Dictionary` (and, in fact, uses a `Dictionary` behind the scenes to store its data). The keys of a `Dictionary` are unordered. In addition, the JSON spec indicates that "[a]n object is an unordered collection of zero or more name/value pairs". IOW, there is no guarantee offered by JSON or by the Codable APIs that the order of an encoded item's keys will correspond to the order of unencoded item's properties. And, really, does it matter? As long as the data from the correct keys gets (en\|de)coded to/from the correct properties, everything is cool. Note that you can ensure that the keys of the resulting JSON are sorted alphabetically by setting `JSONDecoder.outputFormatting = .sortedKeys` but that may or may not be the order you actually want. 2
	@Greenamberred HWS+ Jun '22 I hadn't seen the JSON documentation before, but as it says JSON objects are unordered, then the struct order makes no difference as `@roosterboy` stated. 2
	@blawson3 Jun '22 Sorry, I didn't know that they were unordered. Still learning. Thank you for clarifying!! Bob 2

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