How to filter a list in-place with Kotlin?

Question

In Java I can remove items from a list with this code:

private void filterList(List items) {
    Iterator iterator = items.iterator();
           


        

Answer 1

Kotlin has a lot of neat built-in functions. You can try to use filter here.

val filteredItems = items.filter { checkItem(it) }  

Unfortunately, it will recreate the list. This API was designed on purpose to avoid extra mutability.

But if you still want to proceed with a MutableList use retainAll method

items.retainAll { checkItem(it) }