Hi, is there an idiomatic way to attribute a value...

# getting-started

[Ayfri]

Hi, is there an idiomatic way to attribute a value to a variable if this variable is null ? Other than a if

[Sam]

I guess x = x ?: newValue, but it feels a bit unintuitive

[Johann Pardanaud]

How is this unintuitive? This is quite idiomatic for code written in Kotlin 🙂

[Johann Pardanaud]

you can find this operator in a lot of languages, this is not uncommon 😉

[Sam]

I just didn’t quite like the fact that it does the assignment even when x is not null. It’d feel nicer if there was a way to do it without assigning x to itself.

[Johann Pardanaud]

I can’t assure you this but I don’t think this is an issue since it’s probably optimized by the compiler

[Johann Pardanaud]

you can also just write

if (x == null) x = newValue

it’s not that long

[Jacob]

It would be nice if we could do x ?:= newValue

[Klitos Kyriacou]

That would indeed be nice - it already exists in C#, as ??= (since the C# has ?? as the equivalent of Kotlin's ?:), called the "null-coalescing assignment operator".

[Ayfri]

Yup, there is the same thing in JavaScript

[gildor]

I think it is a questionable feature because it requires x to be mutable and it goes against Kotlin's direction to be immutable as much as possible.
And if is simple and short enough already imo