hi all i have a question regarding best practice, memory, and everything you can share on the subject private var lateinit xyz private var xyz : ABC ?= null what is better?

same for memory

thanks

One big difference is that a nullable property can be set to null again by you or some other code. lateinit is designed for things that are initialized once

if nullable is fine for you (so it doesn’t cause too many unnecessary null checks) I would use nullable

does

isInitialized

cost more then null checks?

No, it's a compiler intrinsic that just does a null check

Why I don’t recommend this, is that if you have 1 case, it may require in future 2 cases, so it become not safe to use, but nullable field is always save, compiler will check it for you, not your runtime

Yes,

lateinit

is a kludge for using frameworks that do "magic field injection", often based on annotations.

If you only need to initialize the variable the first time and you don't need change it more, maybe you can use an immutable approach:

private val xyz: ABC by lazy {}

.

thats something we didn't thought on

you are welcome

Is it any analog of

let

function for lateinit property or just if isInitialized check? Or maybe some extension for it?

If you need

isInitialized

you probably want a nullable property instead.

I thought about creating an extension function for lateinit property, but did not have enough knowledge to implement it. The basic idea is to use a function like the

var?.let{}

function, but with lateinit check

That's not possible, since the type system has no idea about the

lateinit

status of the property.

Thanks for explanation