Samanta  Moore

Samanta Moore


Java ArrayList with Examples

This tutorial describes Java ArrayList in detail. It is a dynamic array that adjusts its size accordingly as elements get added or removed. It is available under the java’s util package.

The native array type is of fixed size and doesn’t allow resizing. You can’t add/remove values from it. To do so, one has to create a new object. On the contrary, the ArrayList grows or shrinks its size automatically as the elements pop in or out.

ArrayList is defined under Java’s collection framework and implements the List interface. Let’s check it out in detail and with the help of examples.

### Java ArrayList Explained with Examples

The following are the points that we are discussing in this Java ArrayList tutorial. Let’s check them out one by one.

**Contents [**[**hide**](**]**

*   [1 ArrayList in Java](
*   [1.1 Syntax](
*   [1.2 Some Keypoints](
*   [2 Create an ArrayList and Add Elements](
*   [3 Create ArrayList from ArrayList and Collection](
*   [4 Access and Remove Elements from ArrayList](
*   [5 Traversing Java ArrayList](
*   [6 Find Elements in ArrayList](
*   [7 Create an ArrayList of User-defined Type (UDT)](
*   [8 Sort Elements in Java ArrayList](
*   [8.1 Collections.sort()](
*   [8.2 ArrayList.sort()](
*   [8.3 User-defined sorting](
*   [9 How to Protect ArrayList from Multiple Threads](
*   [9.1 Accessing Un-synchronized ArrayList](
*   [9.2 Synchronizing ArrayList in Java](
*   [10 Java ArrayList Quick Q&A](
*   [10.1 ArrayList Basics](
*   [10.2 ArrayList vs. Other Collections](
*   [11 Summary](


What is GEEK

Buddha Community

Java ArrayList with Examples
Tyrique  Littel

Tyrique Littel


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


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

Macey  Legros

Macey Legros


Java ArrayList Example | Array List in Java Tutorial

Java ArrayList is a part of the inbuilt collection framework that is used to save the dynamically sized collection of items. Arrays are fixed in size; an ArrayList grows its size automatically when new items are added to it. ArrayList is the part of the collection framework and is present in the java.util package. ArrayList inherits the AbstractList class and implements the List interface.

Important Points about ArrayList in Java

  1. It can be compared as a Vector in C++.
  2. We cannot use primitive data types like char, int, float.
  3. We always need to use wrapper classes like Integer, String, Float, etc.
  4. Java ArrayList allows us to access the list randomly.
  5. An ArrayList is the re-sizable array, also called a dynamic array. It grows its size to accept new elements and contracts the size when the elements are removed.
  6. ArrayList internally uses an array to store the elements. Just like arrays, It allows you to fetch the elements by their index.
  7. Java ArrayList allows duplicate and null values.
  8. Java ArrayList is the ordered collection. It maintains the insertion order of the elements.
  9. Java ArrayList is not synchronized. If the multiple threads try to modify the ArrayList at the same time, then the outcome will be non-deterministic. You must explicitly synchronize access to the ArrayList if multiple threads are going to change it.

#java #java arraylist #java.util #c++

Samanta  Moore

Samanta Moore


Spring Boot and Java 16 Records

In this article, we will discuss Java 16’s newest feature, Records. Then we will apply this knowledge and use it in conjunction with a Spring Boot application.

On March 16th, 2021, Java 16 was GA. With this new release, tons of new exciting features have been added. Check out the release notes to know more about these changes in detail. This article’s focus will be on Java Records, which got delivered with JEP 395. Records were first introduced in JDK 14 as a preview feature proposed by JEP 359, and with JDK 15, they remained in preview with JEP 384. However, with JDK 16, Records are no longer in preview.

I have picked Records because they are definitely the most favored feature added in Java 16, according to this Twitter poll by Java Champion Mala Gupta.

I also conducted a similar survey, but it was focused on features from Java 8 onwards. The results were not unexpected, as Java 8 is still widely used. Very unfortunate, though, as tons of new features and improvements are added to newer Java versions. But in terms of features, Java 8 was definitely a game-changer from a developer perspective.

So let’s discuss what the fuss is about Java Records.

#java #springboot #java programming #records #java tutorials #java programmer #java records #java 16

Seamus  Quitzon

Seamus Quitzon


Learning by Doing: How to Learn Java Basics by Building Your Own Project

Java is not the hardest language to start with. So, it becomes way popular among novice developers joining the ranks of Java coders every single day. If you are reading this blog post, you might be interested in learning Java.

Java is widely used across industry, and especially in the area of Enterprise software, which results in many high paying job opportunities and makes this programming language a common language for newbies. A general promotion of it within colleges and other institutions providing a formal Computer Science education also contributes to its popularity.

However, these are not the only advantages of Java — among other things, it allows you to adopt good practices and makes it way easier to learn other languages in the future. And with no doubt, you can easily learn it if you’re following the right approach. In this post, I am going to share some of them with you.

The Importance of Practice in Programming

Beyond all doubt, practice is important and valuable. But, before we get to the advantages of hands-on experience, I want to draw your attention to one essential thing I often tell my students.

New programmers who are just learning and start implementing things, without being supervised, often end up adapting bad practices. To avoid that, especially when you are making your first steps in programming, I recommend looking for a person who will supervise you and teach you. A strong mentorship with someone engaged in a serious project, as well as communication within the community in the form of sharing code and asking for feedback, is worth the effort. Similarly, when you are applying for your first job, you want to be looking for a company with a strong team and a good leader who would be keen on investing into your learning.

Now, let’s return to practical experience. Learning by doing is different from learning by passively consuming the information. To make sure we can use all the newly acquired technology, we should put our skills to test and write tons of code. The benefits of hands-on experience are almost endless.

Efficiency and Productivity

By practicing, you get a clear understanding of what programming is. Consequently, you start doing better with each new hands-on task, complete it faster, and thus become more productive.

Even if you are not working on real-world projects yet, it’s important to get used to having deadlines. They are inextricably linked to the programming process. My recommendation is to set up your own deadlines while practicing stage and follow them as closely as possible.

#java #learn java #java code #learn java in easy way #learn java course #learn java development