How to declare an ArrayList with values?
This question already has an answer here:
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 useful information that usually contains the answer you're looking for. For example, here are the constructors of the ArrayList class:
ArrayList()
Constructs an empty list with an initial capacity of ten.
ArrayList(Collection<? extends E> c) (*)
Constructs a list containing the elements of the specified collection, in the order they are returned by the collection's iterator.
ArrayList(int initialCapacity)
Constructs an empty list with the specified initial capacity.
Java 8 solution using Stream :
Stream.of("xyz", "abc").collect(Collectors.toList());
你可以这样做：
List<String> temp = new ArrayList<String>(Arrays.asList("1", "12"));
Use:
List<String> x = new ArrayList<>(Arrays.asList("xyz", "abc"));
If you don't want to add new elements to the list later, you can also use (Arrays.asList returns a fixed-size list):
List<String> x = Arrays.asList("xyz", "abc");
Note: you can also use a static import if you like, then it looks like this:
import static java.util.Arrays.asList;
...
List<String> x = new ArrayList<>(asList("xyz", "abc"));
or
List<String> x = asList("xyz", "abc");
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