Introduction to Programming

empty(), of(T t), ofNullable(T t)

The following three methods create either empty or single-element Stream objects: 

• Stream<T> empty(): Creates an empty sequential Stream object.
• Stream<T> of(T t): Creates a sequential single-element Stream object.
• Stream<T> ofNullable(T t): Creates a sequential Stream object containing a single element if the t parameter is non-null; otherwise, creates an empty Stream.

The following code demonstrates the usage of the preceding methods:

Stream.empty().forEach(System.out::println);    //prints nothingStream.of(1).forEach(System.out::println);      //prints: 1List<String> list = List.of("1 ", "2");//printList1(null);                             //NullPointerExceptionprintList1(list);                               //prints: 1 2void printList1(List<String> list){ list.stream().forEach(System. ...