Creating a Kotlin data class without parameters

Question

hope I can get some valued assistance with a little issue I'm trying to work.

I've got an API endpoint which is sending data with the following request schema:

{
  "type": String,
  "coordinates": [
    0.949492,
    48.77163
  ]
}

As can be seen; the coordinates from the search are provided as two INT values, without parameters.

I'm trying to create an automated test for this, and I've put the above in a data class so it can be used all over the suite as-needed.

My data class is currently looking like the below example, but I don't know how to properly define a list for coordinates without a val or var parameter. I've defined it as a var called "list" for now so it stops throwing compilation errors. How should I be representing this list of coordinates?

data class SearchRequest(
    val type: String,
    val coordinates: List<Coordinates>
)


data class Coordinates(
    var list: Int
)

It looks like it's just a list of floating point numbers, so you could define val coordinates: List<Float> in your first class and you don't need a second class. — Tenfour04
– Tenfour04, Commented Oct 10, 2022 at 15:23
Thanks very much for the feedback. Also suggested by another, so definitely the way to go! Thanks again. — tmf88
– tmf88, Commented Oct 10, 2022 at 15:31
You might have realised already, but a data class requires at least one parameter, and all its constructor parameters need to be a val or var. That's what makes it a data class - all its data is the stuff in the constructor params, and that's what's used in its generated copy function, as well as its equals/hashCode/toString overrides. So if you ever do want a class with normal, non-val/var constructor parameters, you need a regular class! (Or maybe a builder function that can set up a data class after constructing it, using your extra params to poke at it) — cactustictacs
– cactustictacs, Commented Oct 10, 2022 at 18:01

Sergio · Accepted Answer · 2022-10-10 15:25:09Z

1

The second parameter is a list of Float values, there is no need to create a separate class for that, Float can be used:

data class SearchRequest(
    val type: String,
    val coordinates: List<Float>
)

answered Oct 10, 2022 at 15:25

Sergio

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1 Comment

tmf88 Over a year ago

Ahh brilliant. So simple, so easy. Your help and answer are very much appreciated!

Odusola Moyosore · Accepted Answer · 2022-10-11 07:09:06Z

0

In addition to the answers above, you can also download a plugin from android studio that does this for you by just pasting the API's JSON format. The plugin name is JSON to Kotlin class converter, I think.👍🏻

answered Oct 11, 2022 at 7:09

Odusola Moyosore

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