Example 1:
This is a lambda expression :
Consumer<String> c = s -> System.out.println(s);
Can be written as below using Method reference :
Consumer<String> c = System.out::println;
Example 2 :
Comparator<Integer> c1 = (i1,i2) -> Integer.compare(i1, i2);
Can be written as below in Method Reference :
Comparator<Integer> c2 = Integer::compare;