how do i use `mapto` plus `takeif` in chain so that only tho kotlinlang #announcements

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Title

s

Syed Faraz

07/19/2019, 9:10 AM

how do i use

mapto

plus

takeif

in chain, so that only those which satisfy operation are mapped to an arraylist?

w

wasyl

07/19/2019, 9:20 AM

You want to take only certain items from the collection, map them to other object, and put everything in an array list? In that case I think it’d be

collection.filter { }.mapTo(arrayList()) { }

t

tseisel

07/19/2019, 9:28 AM

collection.mapNotNullTo(arrayListOf()) { item ->
    item.transform().takeIf { it.satisfiesPredicate() }
}

g

gildor

07/19/2019, 9:29 AM

Yes, Thibault was faster 🙂 mapNotNullTo is the way to do that, but only for non-nullable values

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