List¶

Reverse List¶

The most common and efficient way to reverse a list in Java is using the Collections.reverse()

import java.util.*;

List<String> list = new ArrayList<>(Arrays.asList("A", "B", "C"));
Collections.reverse(list); // list is now ["C", "B", "A"]

Java 21+

Introduced in Java 21 as part of the Sequenced Collections API, this method returns a reversed view of the original list.

List<String> list = new ArrayList<>(Arrays.asList("1", "2", "3"));
List<String> reversedView = list.reversed(); // ["3", "2", "1"]

Can add element at index using

// add element to the front
list.add(0,nums[i]);