Initialization of an ArrayList in one line

Explanation

To Initialization of an ArrayList in one line we can make it simple just by declaring it as a List .

List<String> places = Arrays.asList("Buenos Aires", "Córdoba", "La Plata");

Or in case if you just have only one element at that time use:

List<String> places = Collections.singletonList("Buenos Aires");

This can mean that places is immutable and if you try to change it will cause an exception called as UnsupportedOperationException which will be thrown. 

To make a  list mutable that is a concrete ArrayList . you can simply create an ArrayList from the immutable list:

ArrayList<String> places = new ArrayList<>(Arrays.asList("Buenos Aires", "Córdoba", "La Plata"));

Also read, How do I loop through or enumerate a JavaScript object?