How to display interaction element with order way of list one in Kotlin-CodePudding

I have two lists and I want to return a result in the following way:

the result should contain elements that are in list one and list two
output should be same order as per first list

Input :

val first = listOf(1, 2, 3, 4, 5,7,9,15,11)
val second = listOf(2, 15 , 4,3, 11)

Output:

val output = listOf(2,3,4,15,11)

Please help me to learn how to get common values in both lists in order of list first in Kotlin.

CodePudding user response：

You can do

val output = first.filter { second.contains(it) }

CodePudding user response：

What you are looking for is the intersection of the two lists:

val output = first.intersect(second)

As pointed out by @Ivo the result is a Set which can be turned into a list with output.toList(). However, since the result is a set, it contains no duplicates, e.g. if first is listOf(1,2,3,1,2,3) and second is listOf(2,4,2,4), the result will be equal to setOf(2).

If this is not acceptable, the solution of @Ivo should be used instead.