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

In Java 9 we can easily initialize an ArrayList in a single line:

List places = List.of("Buenos Aires", "Córdoba", "La Plata");

or

List places = new ArrayList<>(List.of("Buenos Aires", "Córdoba", "La Plata"));

This new approach of Java 9 has many advantages over the previous ones:

1. Space Efficiency
2. Immutability
3. Thread Safe

See this post for more details -> What is the difference between List.of and Arrays.asList?