Skip to Content
Java 9: Building Robust Modular Applications
book

Java 9: Building Robust Modular Applications

by Dr. Edward Lavieri, Peter Verhas, Jason Lee
April 2018
Intermediate to advanced content levelIntermediate to advanced
910 pages
33h 21m
English
Packt Publishing
Content preview from Java 9: Building Robust Modular Applications

Lambda leftovers

There are currently two items labeled as leftovers from the lambda work in Java 8. The first is the use of the underscore for unused parameters in lambda declarations. For example, in this very contrived example, all we care about are the Map values:

    Map<String, Integer> numbers = new HashMap<>(); 
    numbers.forEach((k, v) -> System.out.println(v*2)); 

That results in things like this in the IDE:

Once the use of the underscore is allowed, this code will look like this:

    numbers.forEach((_, v) -> System.out.println(v*2)); 

This allows better static checking of unused variables, allowing tools (and developers) to more easily identify ...

Become an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
and much more.
Start your free trial

You might also like

Java 9 High Performance

Java 9 High Performance

Mayur Ramgir, Nick Samoylov
Distributed Computing in Java 9

Distributed Computing in Java 9

Raja Malleswara Rao Malleswara Rao Pattamsetti

Publisher Resources

ISBN: 9781788832823Supplemental ContentOtherPurchase LinkErrata Page