:: (double colon) operator in Java 8

Question

I was exploring the Java 8 source and found this particular part of code very surprising:

//defined in IntPipeline.java
@Override
public fin         


        

Answer 1

Double colon i.e. :: operator is introduced in Java 8 as a method reference. Method reference is a form of lambda expression which is used to refer the existing method by its name.

classname::methodName

ex:-

• stream.forEach(element -> System.out.println(element))

By using Double Colon ::

• stream.forEach(System.out::println(element))