Initialization of an ArrayList in one line

Question

I wanted to create a list of options for testing purposes. At first, I did this:

ArrayList places = new ArrayList();
places.add(\         


        

Answer 1

With Guava you can write:

ArrayList<String> places = Lists.newArrayList("Buenos Aires", "Córdoba", "La Plata");

In Guava there are also other useful static constructors. You can read about them here.

Answer 2

You can use the below statements:

Code Snippet:

String [] arr = {"Sharlock", "Homes", "Watson"};

List<String> names = Arrays.asList(arr);

Answer 3

Try with this code line:

Collections.singletonList(provider)

Answer 4

interestingly no one-liner with the other overloaded Stream::collect method is listed

ArrayList<String> places = Stream.of( "Buenos Aires", "Córdoba", "La Plata" ).collect( ArrayList::new, ArrayList::add, ArrayList::addAll );

Answer 5

If you need a simple list of size 1:

List<String> strings = new ArrayList<String>(Collections.singletonList("A"));

If you need a list of several objects:

List<String> strings = new ArrayList<String>();
Collections.addAll(strings,"A","B","C","D");

Answer 6

Simply use below code as follows.

List<String> list = new ArrayList<String>() {{
            add("A");
            add("B");
            add("C");
}};