How to get the first and last element of a list

Short answer

Since Java 21 lists have getFirst() and getLast():

void main() {
    var queue = List.of("Anna", "Oleg", "Boris");
 
    IO.println(queue.getFirst());
    IO.println(queue.getLast());
}

Output:

Anna
Boris

In older Java versions use get(0) and get(size() - 1):

void main() {
    var queue = List.of("Anna", "Oleg", "Boris");
 
    IO.println(queue.get(0));
    IO.println(queue.get(queue.size() - 1));
}

Output:

Anna
Boris

removeFirst() and removeLast() remove and return the end elements:

void main() {
    var stack = new ArrayList<>(List.of(1, 2, 3));
 
    IO.println(stack.removeLast());
    IO.println(stack);
}

Output:

3
[1, 2]

A stream with findFirst() returns an Optional and does not fail on an empty list:

void main() {
    List<String> empty = List.of();
    IO.println(empty.stream().findFirst().orElse("nobody"));
}

Output:

nobody

Calling getFirst() on an empty list:

void main() {
    List<String> names = new ArrayList<>();
    IO.println(names.getFirst());
}

Output:

Exception in thread "main" java.util.NoSuchElementException

Check isEmpty() before the call.