Kotlin "return" statement for when variable assignment

Question

I want to assign a variable in Kotlin with when:

val clickedBlock: Block? = when (event.action) {
    ...
    Action.RIGHT_CLICK_AIR -> {
        p.getLineOfSight(null, 5).forEach { block ->
            if (block.type != Material.VOID_AIR) {
                block // I want to assign the variable with this
            }
        }
        null // and not always with this
    }
    else -> null
}

But IntelliJ says it would always return the second null value.

How can I achieve it that the variable clickedBlock will be assigned with block (and not null) if the if statement inside of the forEach loop is true without having to introduce another variable?

IR42 · Accepted Answer · 2020-04-30 16:34:53Z

4

You can wrap this in a run function

Action.RIGHT_CLICK_AIR -> run {
    p.getLineOfSight(null, 5).forEach { block ->
        if (block.type != Material.VOID_AIR) {
            return@run block // I want to assign the variable with this
        }
    }
    null
}

but I think it would be better to do this:

Action.RIGHT_CLICK_AIR -> p.getLineOfSight(null, 5).find { block -> block.type != Material.VOID_AIR }

edited Apr 30, 2020 at 16:34

answered Apr 30, 2020 at 16:28

IR42

9,8632 gold badges28 silver badges41 bronze badges

Sign up to request clarification or add additional context in comments.

Collectives™ on Stack Overflow

Kotlin "return" statement for when variable assignment

1 Answer 1

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Your Answer

Sign up or log in

Post as a guest

Related