Jun 17, 2009 · * Implementation detail: It's a private nested class inside java.util.Arrays, named ArrayList, which is a different class from java.util.ArrayList, even though their simple names …

Oct 1, 2008 · Note that the returned type for asList() is a List using a concrete ArrayList implementation, but it is NOT java.util.ArrayList. It's an inner type, which emulates an ArrayList …

May 11, 2021 · You can create Array of ArrayList. List<Integer>[] outer = new List[number]; for (int i = 0; i < number; i++) { outer[i] = new ArrayList<>(); } This will be helpful in scenarios like this. …

And of course, you can create a new object using the constructor that accepts a Collection: List<String> x = new ArrayList<>(Arrays.asList("xyz", "abc")); Tip: The docs contains very …

Oct 20, 2010 · If you want to allow a user to add a bunch of new MyObjects to the list, you can do it with a for loop: Let's say I'm creating an ArrayList of Rectangle objects, and each Rectangle …

Jul 8, 2013 · The problem in. intList = new ArrayList<Integer>(Arrays.asList(intArray)); is that int[] is considered as a single Object instance since a primitive array extends from Object.

Jun 6, 2013 · 1st of all, when you declare a variable in java, you should declare it using Interfaces even if you specify the implementation when instantiating it. ArrayList<ArrayList<String>> …

With Java 9 you can use the List.of(...) static factory method: List<Integer> immutableList = List.of(1, 2); List<Integer> mutableList = new ArrayList<>(List.of(3, 4)); Java 10. With Java 10 …

You are adding a reference to the same inner ArrayList twice to the outer list. Therefore, when you are changing the inner list (by adding 300), you see it in "both" inner lists (when actually …

Apr 24, 2013 · Java 9 allows you to create an unmodifiable list with a single line of ... import java.util.ArrayList ...