How can I turn a List of Lists into a List in Java 8?

Answer 1

We can use flatmap for this, please refer below code :

 List i1= Arrays.asList(1, 2, 3, 4);
 List i2= Arrays.asList(5, 6, 7, 8);

 List> ii= Arrays.asList(i1, i2);
 System.out.println("List>"+ii);
 List flat=ii.stream().flatMap(l-> l.stream()).collect(Collectors.toList());
 System.out.println("Flattened to List"+flat);