I want to get index list as follows.
val a = booleanArrayOf(true,false,true,false)
above code, True number is two. -> indexList = {0, 2} how to get indexList in Kotlin.
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1 Answer
You could use mapIndexed() to get the index and the value of each element, convert to either the index or null, and then remove the nulls...
val b: List<Int> = a.mapIndexed { i, b -> if (b) i else null }.filterNotNull().toList()
Another way would be to use the withIndex() function, filter the values that are true, and map the resulting pairs to the index value. This might be a bit clearer.
val c: List<Int> = a.withIndex().filter { it.value }.map { it.index }
1 Comment
varotariya vajsi
Thanks @Todd, I am using as below example
val indexList: List<Int> = yourList.withIndex().filter { (!it.value.your_custom_object!!.keyName.equals("") && it.value.your_custom_object!!.keyName!!.equals( "some_value", ignoreCase = true )) }.map { it.index }