JDK8 Lambda expressions demo
- 2. Outline Behavior parameterization ? Lambda in nutshell Function Interface Type Checking Local variables and Closure Method reference
- 4. Lambda in nutshell Anonymous Passed around Concise
- 5. Syntax No Arguments One Argument Multiple Arguments With Explicit argument types Multiple Statements
- 6. Function Interface It’s an interface with exactly one abstract method. Example: Runnable, Callable, Comparator. A functional interface can have multiple default methods Functional descriptor
- 7. Common Functional Interfaces in JDK8
- 8. Type Checking new OptSumOfNumbers().findSum(i -> true, numbers); findSum(Predicate<Integer> predicate, List<Integer> numbers) What is the functional descriptor for predicate ? Functional descriptor Integer -> boolean matches lambda expression. Target Type: Predicate<Integer> Integer -> boolean
- 9. Restrictions on local variables & Closure Demo
- 10. Method reference Lambda Method Reference Equivalent (TripModel trip) -> trip.getTripId() TripModel::getTripId (String s) -> System.out.println(s) System.out::println (str, i) -> str.substring(i) String::substring () -> Thread.currentThread().dumpStack() Thread.currentThread()::dumpStack
- 11. Method reference A method reference to a static method. A method reference to an instance method of an object of a particular type. A method reference to an instance method of an existing object. A method reference to a constructor.
Editor's Notes
- #7: Signature of the abstract method is very important since we use it describe the signature of Lambda expression. We can this abstract method as function descriptor.