Samanta  Moore

Samanta Moore

1624974840

Functional Interfaces in Java 8

Introduction

Functional interface is an interface that consists of one abstract method. These interface can show only one functionality. Beyond Java 8, _lambda expressions _can be used to represent the instance of a functional interface. Functional Interfaces can contain any number of default methods. ConsumerPredicate, Function, Unary Operator, Binary Operator are some of the examples of predefined functional interfaces.

Points to remember which are allowed and which are not allowed in a functional interface:

  • In any functional interface, single abstract method is allowed.
  • In a functional interface, more than one abstract method cannot exist.
  • We can have more than one abstract method if we remove @FunctionalInterface  annotation, but that interface cannot be functional interface.

From functional interface if we remove @FunctionalInterface annotation, it must be valid. We use an annotation so that only single abstract method can be present. In functional interface we can provide implementations as the default methods inside interface.

#functional programming #java #java #java 8 #functional interfaces #functional interfaces in java 8

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Functional Interfaces in Java 8
Samanta  Moore

Samanta Moore

1624974840

Functional Interfaces in Java 8

Introduction

Functional interface is an interface that consists of one abstract method. These interface can show only one functionality. Beyond Java 8, _lambda expressions _can be used to represent the instance of a functional interface. Functional Interfaces can contain any number of default methods. ConsumerPredicate, Function, Unary Operator, Binary Operator are some of the examples of predefined functional interfaces.

Points to remember which are allowed and which are not allowed in a functional interface:

  • In any functional interface, single abstract method is allowed.
  • In a functional interface, more than one abstract method cannot exist.
  • We can have more than one abstract method if we remove @FunctionalInterface  annotation, but that interface cannot be functional interface.

From functional interface if we remove @FunctionalInterface annotation, it must be valid. We use an annotation so that only single abstract method can be present. In functional interface we can provide implementations as the default methods inside interface.

#functional programming #java #java #java 8 #functional interfaces #functional interfaces in java 8

Tyrique  Littel

Tyrique Littel

1600135200

How to Install OpenJDK 11 on CentOS 8

What is OpenJDK?

OpenJDk or Open Java Development Kit is a free, open-source framework of the Java Platform, Standard Edition (or Java SE). It contains the virtual machine, the Java Class Library, and the Java compiler. The difference between the Oracle OpenJDK and Oracle JDK is that OpenJDK is a source code reference point for the open-source model. Simultaneously, the Oracle JDK is a continuation or advanced model of the OpenJDK, which is not open source and requires a license to use.

In this article, we will be installing OpenJDK on Centos 8.

#tutorials #alternatives #centos #centos 8 #configuration #dnf #frameworks #java #java development kit #java ee #java environment variables #java framework #java jdk #java jre #java platform #java sdk #java se #jdk #jre #open java development kit #open source #openjdk #openjdk 11 #openjdk 8 #openjdk runtime environment

Samanta  Moore

Samanta Moore

1624948542

Lambda Expression in Java 8

In this blog we will understand what is the lambda expression and why we need lambda expression and how we use lambda and about the functional interface.

What is Lambda Expression :
  • It is an anonymous function.
  • Not having name
  • No return type and no modifiers.

#functional programming #java #functional java #java #java 8 #java8 #lambda expressions in java

Tia  Gottlieb

Tia Gottlieb

1597891740

Functional Interface Explained in Detail Introduced From Java 8

Functional interfaces are introduced as part of Java 8. It is implemented using the annotation called @FunctionalInterface. It ensures that the interface should have only one abstract method. The usage of the abstract keyword is optional as the method defined inside interface is by default abstract. It is important to note that a functional interface can have multiple default methods (it can be said concrete methods which are default) but only one abstract method. The default method has been introduced in interface so that a new method can be appended in the class without affecting the implementing class of the existing interfaces. Because prior to java 8 the implementing class of an interface has to implement all the abstract methods defined in the interface.

The functional interface has been introduced in Java 8 to support the lambda expression in java 8 on the other hand it can be said lambda expression is the instance of functional interface.

For example:

The full implementation of the above functional interface details is available in GitHub, the link of which will be provided at the end of this tutorial.

In Java 8 there are 4 main functional interfaces are introduced which could be used in different scenarios. These are given below.

  1. Consumer
  2. Predicate
  3. Function
  4. Supplier

Among the above four interfaces, the first three interfaces also have extensions also which are given below.

Consumer - BiConsumer

Predicate – BiPredicate

Function – BiFunction, UnaryOperator, BinaryOperator

  1. CONSUMER

Let’s discuss about Consumer.

  • The consumer interface accepts one argument but there is no return value.
  • The name of function inside this interface is accept.

#java #tutorial #java 8 #functional interface #function

Samanta  Moore

Samanta Moore

1620458875

Going Beyond Java 8: Local Variable Type Inference (var) - DZone Java

According to some surveys, such as JetBrains’s great survey, Java 8 is currently the most used version of Java, despite being a 2014 release.

What you are reading is one in a series of articles titled ‘Going beyond Java 8,’ inspired by the contents of my book, Java for Aliens. These articles will guide you step-by-step through the most important features introduced to the language, starting from version 9. The aim is to make you aware of how important it is to move forward from Java 8, explaining the enormous advantages that the latest versions of the language offer.

In this article, we will talk about the most important new feature introduced with Java 10. Officially called local variable type inference, this feature is better known as the **introduction of the word **var. Despite the complicated name, it is actually quite a simple feature to use. However, some observations need to be made before we can see the impact that the introduction of the word var has on other pre-existing characteristics.

#java #java 11 #java 10 #java 12 #var #java 14 #java 13 #java 15 #verbosity