Java 25 (LTS) reference · 10 entries
Java List and ArrayList Methods
List and ArrayList methods: List.of(), add(), get(), set(), remove(), contains(), indexOf(), sort() and subList(), with the common traps explained and runnable examples.
ArrayList is the everyday mutable list; List.of() creates an immutable one. Indexes start at 0.
| Name | Description | Since |
|---|---|---|
List.of() |
Create an immutable list from values. Adding or removing later throws UnsupportedOperationException. | Java 9 |
list.add() |
Append an element to the end of a list, or insert it at an index, shifting later elements right. | Java 1.0 |
list.get() |
Return the element at an index (0-based). Throws IndexOutOfBoundsException for an invalid index. | Java 1.0 |
list.set() |
Replace the element at an index and return the old value. The list's size doesn't change. | Java 1.0 |
list.remove() |
Remove an element by index or by value. With a List<Integer>, remove(1) removes index 1, not the value 1. | Java 1.0 |
list.size() |
Return the number of elements in a list. isEmpty() is a clearer way to check for zero. | Java 1.0 |
list.contains() |
Return true if the list holds an element equal to the given one (using equals()). O(n) for ArrayList. | Java 1.0 |
list.indexOf() |
Return the index of the first element equal to the given one, or -1. lastIndexOf() searches from the end. | Java 1.0 |
list.sort() |
Sort a list in place with a Comparator, or by natural order when you pass null. Collections.sort() does the same. | Java 8 |
list.subList() |
Return a view of part of a list, from an index up to (not including) another. Changes to the view affect the original. | Java 1.0 |