Why can't I initialize a "@Transient" property in ...

# getting-started

[Vladimir Vainer]

Why can't I initialize a "@Transient" property in init block?

Serializable
data class Item(
    val count: Int,
    val price: Int
) {
   @Transient
   val totalPrice = count*price //this works
   @Transient
   val totalPrice2 //This property is marked as @Transient and therefore must have an initializing expression

   init {
      totalPrice2 = count*price //this does not
   }
}

[Alex Prince]

because it's a Val. Vals are immutable and have to be set where they're declared.

If you want to do it in the init block, you could make it a var (though then you lose the immutablility, which, to me anyway, is less than ideal)

[Vladimir Vainer]

If the property is not marked as @Transient
I can init val inside init block

[Alex Prince]

corrected my msg but lateinit would also require the var I think, need more coffee

[Chris B]

It does.

[Vladimir Vainer]

There is inconsistency.
If i have a val property that is not transient, but initialize it with default value,
It behaves like transient anyway.

But if i move the initialization to the init block, then it's no longer transient.

The question is what the difference?
If i initialize someting in the init block, it's the same as default value, it's still a val.
So why it doesn't work

[Michael Krussel]

I do wonder if this is something special due to data class or Serializable class or both.

I know in general (on JVM) if you initialize in the constructor things have the default value in the parent class init block.