Is there an kotlin equivalent of ?: java operator?

Question

Reluctant kotlin newbie here.

I tried searching on google. Most results talk about ?: (elvis operator) in kotlin.

Looking for a way to write this in kotlin:

//java example
//return condition ? a : b;

Does this answer your question? [Kotlin Ternary Conditional Operator](https://stackoverflow.com/questions/16336500/kotlin-ternary-conditional-operator) — ShadowRanger, Feb 19 '20 at 17:01

score 3 · Answer 1 · answered Feb 19 '20 at 16:56

3

kotlin doesn't have ternary operator, but you can use if, when, try catch as expression

return if (condition) a else b

answered Feb 19 '20 at 16:56

IR42

In Kotlin, `if (…) … else …` effectively _is_ a ternary operator: it takes three expressions, and returns a value. It may not _look_ like most other operators, but it's doing exactly the same as the Java/C-style `… ? … : …`. (Which is why Kotlin doesn't need the latter.) – gidds Feb 19 '20 at 17:47

score 2 · Answer 2 · answered Feb 19 '20 at 16:57

? : is a tenary operator which is currently not present in Kotlin. There are few discussions on adding this operator to the language e.g. KT-5823 Support ternary conditional operator 'foo ? a : b' .

The usual suggestion is to use an if statement as replacement.

score 2 · Answer 3 · answered Feb 19 '20 at 17:12

2

The Kotlin equivalent is:

if (a) b else c

That's the closest to the Java that you can get at this point.

answered Feb 19 '20 at 17:12

score 1 · Answer 4 · answered Feb 19 '20 at 17:21

1

The nicest way to do it is this:

return when {
    condition -> a 
    else -> b
}

answered Feb 19 '20 at 17:21

EpicPandaForce

Why would this be the "nicest"? Using `if (a) b else c` seems the obvious choice. – al3c Feb 19 '20 at 17:45
Because `b` is equally important to `a`, and are on the same level of horizontal positioning, thus making code more readable. It is also easier to modify, etc. – EpicPandaForce Feb 19 '20 at 23:35

4 Answers4