why do we make bindings `lateinit` ? we are gonna ...

# getting-started

[Gamar Mustafa]

why do we make bindings lateinit ? we are gonna use that property as soon as our activity/fragment is created, so what's the goal/gain here by using lateinit?

[Joffrey]

What would you suggest as an alternative?

[Gamar Mustafa]

just making it null, and then assigning value to it onCreate/onCreateView?

[Joffrey]

Then you would have to deal with nullability every time you access it. You could technically assign null to it as well, so you would have less safety in this respect

[Gamar Mustafa]

what about creating two properties like _binding and binding? one immutable and one mutable. then we wouldn't have to deal with nullability

[Joffrey]

Could you please spell that out in actual code? I fail to see how that would be better than lateinit

[mohamed rejeb]

Yes you could do it like _binding but you need to know that we do that in purpose, so we can clear the binding and set it back to null in onDestroy to make it eligible for garbage collection, if you have this use case you can do it this way, otherwise lateinit is enough.

[Gamar Mustafa]

@Joffrey I am not saying it's better than lateinit . I just want to know what we gain by using lateinit .

private var _binding: FragmentMyBinding? = null
    private val binding get() = _binding!!

    //or

    private lateinit var binding: FragmentMyBinding

if we don't gain anything by using lateinit , why people still use it instead of using the first approach? I still can make _binding null to clear the binding.

[Joffrey]

To answer what we gain by using lateinit, I need to know what you're comparing it to. The code you provided still allows code to set the _binding property to null later, so binding doesn't have a clear scope for its safe usage. The error thrown by binding would also be quite generic. If you want to fix these little details, you'll end up with even more code. But to be frank this pattern is exactly what the lateinit syntax is meant to express. So basically by using lateinit you have less code, you express the intent better, and it's slightly more constrained.

[hfhbd]

I wish, there would be lateinit val

[mohamed rejeb]

Lazy is lateinit val

[Gamar Mustafa]

So basically by using it you have less code, you express the intent better, and it's slightly more constrained

this is what I was inquiring about. Thanks @Joffrey!

[hfhbd]

You can’t use lazy if you assign the value from another call/scope, like in createBindings

[Javier]

In activities, as I didn't need nullability, I was using val + Lazy without issues