A functional interface is an interface that meets the following condition:
It uses a lambda expression in one of its default methods.
It has a single abstract method or a single method requirement.
It implements the
Lambda<T, U>
interface.
You can create an instance of a functional interface with:
Lambda expressions, method references, or constructor references.
Only lambda expressions. Method references and constructor references only work with
Predicate<T>
.Method references and constructor references. Lambda expressions only work with
Predicate<T>
.
The
IntPredicate
functional interface represents a function with:One argument of the
int
type that returns no result (void
).One argument of the
int
type that returns anInteger
result.One argument of the
int
type that returns aboolean
result.
When we apply a
filter
method to aStream<T>
, the method returns:A
Stream<T>
.A
List<T>
.A
Map<T, List<T>>
.
Which of the following code snippets...
Java 9 with JShell
By :
Java 9 with JShell
By:
Overview of this book
The release of Java 9 has brought many subtle and not-so-subtle changes to the way in which Java programmers approach their code. The most important ones are definitely the availability of a REPL, known as JShell, which will make experiments and prototyping much more straightforward than the old IDE-based project-led approach. Another, more subtle change can be seen in the module system, which will lead to more modularized, maintainable code. The techniques to take full advantage of object-oriented code, functional programming and the new modularity features in Java 9 form the main subjects of this book.
Each chapter will add to the full picture of Java 9 programming starting out with classes and instances and ending with generics and modularity in Java.
Table of Contents (23 chapters)
Java 9 with JShell
Credits
About the Author
Acknowledgement
About the Reviewer
www.PacktPub.com
Customer Feedback
Preface
Free Chapter
JShell – A Read-Evaluate-Print-Loop for Java 9
Real-World Objects to UML Diagrams and Java 9 via JShell
Classes and Instances
Encapsulation of Data
Mutable and Immutable Classes
Inheritance, Abstraction, Extension, and Specialization
Members Inheritance and Polymorphism
Contract Programming with Interfaces
Advanced Contract Programming with Interfaces
Maximization of Code Reuse with Generics
Advanced Generics
Object-Oriented, Functional Programming, and Lambda Expressions
Modularity in Java 9
Exercise Answers
Index
Customer Reviews