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kotlinlang

Is_this_a_bug_or_a_user_error_.txt

I just don't understand the difference or why one of them fails.

You’re simply not initializing `master` before `data`

Remember that the constructor of the superclass is called BEFORE the constructor of any subclass, so `master` stays null during the entire execution of the abstract class constructor

This comment
&gt; I know the `get()` is unnecessary
It’s completely wrong, these two are two very different things:
```
val x: Int get() = y
```
```
val x: Int = y
```

But it crashes on access to `hash`, not during construction - or am I way out here? Note that this is an `abstract` and there `is` a `master` at that time is there not?
So what *is* the difference and why does changing `data` make `hash` work?

<https://kotlinlang.org/docs/reference/properties.html>

Your error clearly state that `master` is null in case you didn’t see

Yes! `master` is `null` when I request the `hash` and that is long after the actual object has finished construction.
```
object FooImageData : ImageData() {
    override val master = listOf(
        "424d3684030000000000..."
        // ...
    )
}```

Well that’s just not possible so I’m gonna keep saying your object hasn’t finished construction yet the first time you call `hash`

&gt; Well that’s just not possible
My feelings exactly! Which is why I chose to ask here. :slightly_smiling_face: