< joelpedraza> Great minds and all that slightly smiling face

Which is preferred kotlinlang #announcements

01/03/2019, 4:44 PM

Which is preferred?

01/03/2019, 4:47 PM

Depends on the use case but without further context I'd either do 2 or

class ClassName {
    companion object {
        private const val CONST_VALUE = "value"
    }
}

01/03/2019, 4:47 PM

Short answer: 2 (or in a

ClassName

companion object, but I prefer top level)

01/03/2019, 4:47 PM

@joelpedraza Great minds and all that 🙂

01/03/2019, 4:49 PM

I put them at the top level as well

01/03/2019, 4:50 PM

why companion? I prefer to not use companion If at all possible.

01/03/2019, 4:51 PM

As a rule I go with top level for private const, companion for public (to avoid polluting the global namespace)

01/03/2019, 4:51 PM

If the value is only used with the class, it makes the intent more clear.

01/03/2019, 4:54 PM

The drawback of top level is that your Kotlin class file becomes Kotlin file. You loose the association between file and class in the IDE

I think creating companion for storing constants is overkill

01/03/2019, 5:00 PM

Tangential to the rest of the conversation: Either way a new class is created

01/03/2019, 5:01 PM

not with option 1 if I'm not wrong

01/03/2019, 5:02 PM

No, not for option 1, but that won't actually be a compile time constant.

01/03/2019, 5:03 PM

True but then every instance of your class has a field to hold what should be a shared static or const

If it’s a concern for you any tree shaking optimization will remove it. IIRC consts are inlined for kotlin usages, but java usages access the field

01/03/2019, 5:10 PM

@joelpedraza You mean the field in option 1?

01/03/2019, 5:11 PM

No, top level or companion