:: (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

:: is a new operator included in Java 8 that is used to refer a method of an existing class. You can refer static methods and non-static methods of a class.

For referring static methods, the syntax is:

ClassName :: methodName 

For referring non-static methods, the syntax is

objRef :: methodName

And

ClassName :: methodName

The only prerequisite for referring a method is that method exists in a functional interface, which must be compatible with the method reference.

Method references, when evaluated, create an instance of the functional interface.

Found on: http://www.speakingcs.com/2014/08/method-references-in-java-8.html