How to get the first element of the List or Set? [duplicate]

Answer 1

java8 and further

Set set = new TreeSet<>();
    set.add("2");
    set.add("1");
    set.add("3");
    String first = set.stream().findFirst().get();

This will help you retrieve the first element of the list or set. Given that the set or list is not empty (get() on empty optional will throw java.util.NoSuchElementException)

orElse() can be used as: (this is just a work around - not recommended)

String first = set.stream().findFirst().orElse("");
set.removeIf(String::isEmpty);

Below is the appropriate approach :

Optional firstString = set.stream().findFirst();
if(firstString.isPresent()){
    String first = firstString.get();
}

Similarly first element of the list can be retrieved.

Hope this helps.