collections – Page 3

Size-limited queue that holds last N elements in Java

October 12, 2022 by Tarik

Apache commons collections 4 has a CircularFifoQueue<> which is what you are looking for. Quoting the javadoc: CircularFifoQueue is a first-in first-out queue with a fixed size that replaces its oldest element if full. import java.util.Queue; import org.apache.commons.collections4.queue.CircularFifoQueue; Queue<Integer> fifo = new CircularFifoQueue<Integer>(2); fifo.add(1); fifo.add(2); fifo.add(3); System.out.println(fifo); // Observe the result: // [2, 3] If … Read more

Kotlin’s List missing “add”, “remove”, Map missing “put”, etc?

October 8, 2022 by Tarik

Unlike many languages, Kotlin distinguishes between mutable and immutable collections (lists, sets, maps, etc). Precise control over exactly when collections can be edited is useful for eliminating bugs, and for designing good APIs. https://kotlinlang.org/docs/reference/collections.html You’ll need to use a MutableList list. class TempClass { var myList: MutableList<Int> = mutableListOf<Int>() fun doSomething() { // myList = … Read more