10 Tools Every Software Developer/Programmer Should Learn in 2023 [UPDATED]

Every trade has its tools, and software development is no different. A good programmer or software developer generally knows their tools better than others and also has access to more powerful and advanced tools than an average programmer, but there are certain tools that you expect every software developer should know, and this list is all about such tools. In this list, I am going to share 10 essential tools, which I believe every programmer or software developer should know and know well. These tools will not only make you a better programmer but also you will be able to do a lot of your day to day tasks quickly and more confidently. Having these tools in your resume also acts like magnet and it will bring more calls from recruiters in 2023.

Top 10 Gift Ideas for Programmers, Software Engineers, and Tech Geeks in 2023

Hello guys, it's that time of the year again when we buy gifts for our loved ones, friends, and colleagues. If you are looking for gift ideas for your programmer friends and colleagues then you have come to the right place. My friend circle has a lot of programmers and non-programmers. When it comes to buying gifts for birthdays, anniversaries, or holidays, I receive a lot of queries from my non-programmer family and friends about what to buy for a programmer? Well, buying a gift is easy but choosing or finding the right gift for someone is really really tough. I have had this experience when it comes to buying gifts for kids. 

Top 22 Libraries and APIs Java Developer should Learn in 2023 [UPDATED]

One of the traits of a good and experienced Java developer is the extensive knowledge of API, including JDK and third-party libraries. I spent a good deal of time learning API, especially after reading Effective Java 3rd Edition, where Joshua Bloch has advised us to use the existing API for development rather than writing new pieces of code for common stuff. That advice makes sense to me because of the testing exposure these 2nd party libraries get. In this article, I am going to share some of the most useful and essential libraries and APIs, a Java developer should be familiar with. Btw, I am not including frameworks like Spring and Hibernate because they are pretty well known and have specific features.

10 Microsoft Azure Cloud Certifications You can Aim in 2023 - Best of Lot

Hello guys, if you are aiming to become an Azure certified professional and looking for top 10 Azure certifications then you have come to the right place. Earlier, I have shared many best AWS certifications and many free courses to learn AWS, GCP, and today I am going to share the top 10 Azure certifications you can aim for in 2023. Cloud computing technology is growing almost faster than any other industry and in fact, the growth has increased by 17% in 2023 compared to the last year, and that because of many facts like the tremendous increase in SaaS companies as well as the power you get compared to what you paid for made a lot of people thinking to use the cloud to store their websites and running their businesses.

Top 6 Career Options for Experienced Java Developers in 2023 [UPDATED]

Hello guys, If you are an experienced Java programmer who has done a good amount of coding and development, like someone with more than 5 to 8 years of experience, working as a senior Java developer or a technical lead and wondering how to grow to the next level, then you have come to the right place. In this article, I'll share six career options and Jobs experienced developers like you can choose to take your career to the next level. Apart from becoming a project manager, which is what many programmers wanted, there are other more technical and better career opportunities are available now. It's especially great for Programmers with less or no people management skills or who love coding and development and always want to remain hands-on.

10 Tools Used by Java Programmers in Day to day life [UPDATED for 2023]

Every trade has its tools, and Java programming is no exception. In fact, good knowledge of tools and mastery of using them saves a lot of time in design, development, testing, debugging, and troubleshooting any production issue. To become a good developer, you must know the right tools for the right jobs. A developer without tools and tricks is like a toothless lion; hence you must devote some time to learning the tools required for your day-to-day job. Many developers think that learning an IDE like Eclipse, NetBeans, or IntelliJ IDEA is enough, but that's just the start of the process. No doubt that IDEs are the most important tool ever created for programmers, but they are not the solution for everything.

10 Things Java Programmers Should Learn in 2023 [UPDATED]

It's 27th December now, and only a few days have left in the year 2022, one of the years which brings joy and freedom after 2 years of lockdown. Now, it's time to look back and retrospect on what you have achieved in 2022 and what you could have done better, despite all the challenges 2022 has thrown to all of us. This will also help you to create your goals for 2023. As a programmer, our biggest challenge is to keep ourselves up-to-date. Technology changes very fast, and you will see a new version of programming language and framework coming to every couple of years. This year has plentiful changes with keeping up-to-date with a new Java version every 6 months, Spring 6.0, Spring Security 6.0, and Spring Boot 3; it's probably the busiest year in terms of changes for Java developers.

Top 5 Christmas and New Year Gifts for Programmers and Developers in 2023 [UPDATED]

Hello guys, Season's greetings to everyone. May God bless you with success and whatever you want coming new year. This is festival time and I have a couple of friends asking me what to gift to a programmer friend or colleague? This is a common confusion you face when buying a gift for tech geeks, software engineers, programmers, and web developers. Everybody wants that their gift to be well received and make the person excited and happy. Being a Java programmer myself, I am going to suggest a couple of things which I have recently bought for my programmer friends, colleagues, and relatives. 

Is Java Pass by Value or Pass by Reference? Example

Hello guys, Does Java is pass by value or pass by reference is one of the tricky Java questions mostly asked on both beginner and experienced level Java developer interviews. Before debating whether Java is pass by value or pass by reference lets first clear what is pass by value and what is pass by reference actually means?. This question has its origin in C and C++ where you can pass function parameter either value or memory address, where value is stored (pointer). As per Java specification everything in Java is pass by value whether its primitive value or objects and it does make sense because Java doesn't support pointers or pointer arithmetic, Similarly multiple inheritance and operator overloading is also not supported in Java.

3 ways to convert String to Boolean in Java? Examples

Hello guys, if you ar wondering how to convert a String object to boolean value in Java then don't sweat there are multiple ways to convert a String to Boolean class or boolean value in Java. For Example, ou can convert a String object to a Boolean object or boolean primitive by using the Boolean.valueOf() and Boolean.parseBoolean() method. The steps are similar rot converting to String to other data types  like String to Integer and String to Long. You can use the valueOf() method to convert String to Boolean object and parseBoolean() method to convert a given string to a boolean primitive value. Internally, valueOf() also uses parseBoolean() for parsing String but on top of that it also provides caching e.g. it can return Boolean.TRUE and Boolean.FALSE cached value for "true" and "false" strings. 

Top 10 Black Friday + Cyber Monday Deals for Programmers - Best of Lot [2023 UPDATED]

Hello my programmers and developers friends, Black Friday and Cyber Monday are almost here and if you have been waiting for this period to buy the stuff you love then your wait is finally over as all the big brands like Udemy, Pluralsight, Educative, CodeCademy, DataCamp, Coursera , Amazon, Apple all are running discount and Black Friday and Cyber Monday Deals. It's easy to get lost in this myraid of deals but not to afraid as I am sharing the best Black Friday and Cyber Monday deals 2023 for Programmers, Developers, Coders, and my Techie friends. In this post you will find the deals which  can help you in your learning as well as things you love. 

5 Best Thinkific, Teachable, Podia, and Learn Worlds Deals & Discounts Coupons [UPDATED]

Hello guys, I have been advocating for programmers and developers to create online courses to both learn and earn in 2023 for quite some time and have been recommending Thinkific, LearnWorlds, Podia, and Teachable to create their online courses and share their knowledge. A lot of you asked about discount coupons and deals to get started and that's why I am sharing the best discount offers for both Thinkific and Teachable platforms to create your online course business in 2023. In today's world, there is no better way to teach than creating courses and this pandemic has proved that e-learning is going to stay and increase in near future. 

Top 5 Courses to Learn SQL and Database in 2023 - Best of Lot

Hello guys, if you are a computer science graduate or new to the programming world, interested in learning SQL, and looking for some excellent resources, like books, courses, and tutorials to start with, then you have come to the right place. In the past, I have shared some of the best SQL books and tutorials, and today I am going to share some of the best SQL and database courses to learn and master this useful technology. If you don't know what SQL is and why you should learn it, let me give you a brief overview of SQL for everyone's benefit. SQL is a programming language to work with a database. You can use SQL to create database objects, like tables, stored procedures, etc., and also to store and retrieve data from the database.

How to Enable log SQL statements in Spring Boot? Example Tutorial

Hello guys, if you are a Java developer developing Spring Boot applications, you may need to have proper knowledge of various kinds of errors and also how to overcome those. For example, most of Java developers use JPA in spring boot to make our work easy when managing databases. If you get an error like an internal server error (504 error), you need to go through your backend system and find the error. In many cases, these errors are caused by running invalid SQL or due to error on database. At that time, you often need to know which SQL statements are executed by Hibernate or JPA, or any other database library you are using.  

Difference between CAST, CONVERT, and PARSE SQL Server? Example Tutorial

Though all three, CAST, CONVERT, and PARSE are used to convert one data type into another in SQL Server, there are some subtle differences between them. The  CAST method accepts just two parameters, expression, and target type, but CONVERT() also takes a third parameter representing the format of conversion, which is supported for some conversions, like between character strings and date-time values. For example, CONVERT(DATE, '2/7/2015', 101) converts the character string '2/7/2015' to DATE using DATE format 101, representing United States standard.

Is CodeGym Good Place to Learn Java? Is CodeGym Premium Worth it?

>Hello guys, if you are learning Java or want to learn Java but not sure if CodeGym is the right place for you or not then you have come to the right place. Earlier, I have shared best places to learn Java coding for FREE and in this article, I will review CodeGym, one of the interactive platform to learn Java. But, Before we see whether CodeGym is worth it for learning and mastering Java, let me tell you a little bit about what CodeGy really is.   CodeGym is an excellent and innovative alternative to traditional learning platforms like Udemy and Coursera. It is basically a platform that is designed for young and passionate people who want to learn Java. The CodeGym platform aims to deliver practical learning with the help of games that can make learning fun and interesting.

Difference between @Mock and @MockBean in Spring Boot? Example Tutorial

Hello guys, if you are writing test for your your Spring Boot application then Sooner or later, you'll come across @Mock and @MockBean annotations while testing your Spring Boot application. Both annotations generate fake or Mock  objects, but for different reasons and its important for Java and Spring Boot developer to know the correct difference and when to use @Mock and @MockBean while writing tests. It's possible that this will seem perplexing at first, in face I was confused for a long time until I did my research and cleared it up. But, you don't need to scan through internet, In this blog article, I'll clear up any misunderstandings and clarify the difference between @Mock and @MockBean when testing Spring Boot apps.

Difference between State and Strategy Design Pattern in Java

Hello guys, if you are wondering what is difference between State and Strategy pattern in Java then you are at the right place. In order to make proper use of State and Strategy design Patterns in any Java application, it's important for a Java developer to clearly understand the difference between them. Though both State and Strategy design patterns have a similar structure, and both of them are based upon the Open closed design principle, which represents 'O' from SOLID design principles, they are totally different on their intent. The strategy design pattern in Java is used to encapsulate a related set of algorithms to provide runtime flexibility to the client. 

Decorator Design Pattern in Java with Example Java Tutorial

Hello guys, if you want to learn about Decorator design pattern in Java then you are at the right place. I was thinking to write on decorator design pattern in Java when I first wrote 10 interview questions on Singleton Pattern in Java. Since design patterns are quite important while building software and it’s equally important on any Core Java Interview, It’s always good to have a clear understanding of various design patterns in Java. In this article, we will explore and learn the Decorator Design pattern in Java which is a prominent core Java design pattern and you can see a lot of its examples in JDK itself. 

Data Access Object (DAO) design pattern in Java - Tutorial Example

Data Access Object or DAO design pattern is a popular design pattern to implement the persistence layer of Java application. DAO pattern is based on abstraction and encapsulation design principles and shields the rest of the application from any change in the persistence layer e.g. change of database from Oracle to MySQL, change of persistence technology e.g. from File System to Database. For example, if you are authenticating the user using a relational database and later your company wants to use LDAP to perform authentication. If you are using the DAO design pattern to access the database, it would be relatively safe as you only need to make a change on Data Access Layer. DAO design pattern also keeps the coupling low between different parts of an application.

How to Convert a Map to a List in Java - Example Tutorial

Hello guys, if you are wondering how to convert a Map like HashMap or TreeMap to a List like ArrayList or LinkedList in Java then you are at the right place. Earlier, I have shared 10 examples of converting a List to Map in Java and this article, I am going to share my tip to convert a given Map to a List in Java. Map and List are two common data structures available in Java and in this article, we will see how can we convert Map values or Map keys into List in Java. The primary difference between Map (HashMap, ConcurrentHashMap, or TreeMap) and List is that Map holds two objects key and value while List just holds one object which itself is a value. 

How to use mkdir command to make directories in Linux and UNIX? mkdir -p Example

One of the most common tasks in any Linux is creating directories, and most of us spend a lot of time creating complex directory structures in UNIX and Linux.  I am sure you know about the mkdir command, we have been using this command in almost every operating system like DOS, Windows, Linux, OS/2, Solaris, or any other *NIX operating system. It is one of the basic commands but as important as find, grep or chmod.  mkdir stands for "make directory" and this command is literally used to create directories. Suppose, you need to create a directory tree-like /opt/software/java/app/config, how are you going to create these directories? One by one right? Well, yes you can use mkdir and command to create these directories one by one as shown in below example :

How hostname to IP address Conversion works in Linux? nslookup Example

One of my favorite Linux Interview questions is about how to convert hostname to IP address in Linux? These questions not just test the candidate's basic Linux command skills but also shows his understanding of how name resolution works in UNIX or Linux? Many developers, software engineers, and support professionals don't really know how Linux converts a hostname into IP address or what happens when they type http://www.amazon.com in their browser in UNIX? They are not really familiar with how the name amazon.com is resolved to an IP address.

How to Delete Empty Files and Directories in UNIX or Linux Host? find Command Example

Deleting empty file and directory in Unix

Hello guys, if you are wondering how to find and remove all empty files and directories from a Linux host then you are at the right place. Earlier, I have shared Linux command to free disk space by removing big files and directories and in this article, I will share find command you can use to remove empty files and directories. Many times we need to find and delete empty files or directories in UNIX/Linux. Since there is no single command in Unix/Linux which allows you to remove empty files or empty directories rather we need to rely on find command and xargs command. 

Difference between HashMap, LinkedHashMap and TreeMap in Java with Example

Hello guys, if you are wondering what is difference between HashMap, TreeMap, and LinkedHashMap in Java and when to use them then you are at the right place. In past, I have shared frequently asked HashMap Interview questions and ConcurrentHashMAp Interview questions and today, I Will answer this question in detail. The java.util.Map is one of the most important interfaces from the Java Collection Framework.  It provides hash table data structure functionality by its implementations like HashMap, Hashtable, LinkedHashMap, and a little bit of sorting with the TreeMap. So if you are looking to store key-value pairs in the Java program,  you have a wide range of choices available depending upon your requirement. The main difference between LinkedHashMap, TreeMap, and HashMap comes in their internal implementation and specific features, which a Java programmer should know to use them effectively. 

4 Example to Iterate over Map, HashMap, Hashtable or TreeMap in Java

There are multiple ways to iterate, traverse or loop through Map, HashMap, or TreeMap in Java and we are all familiar with either all of those or some of those. But to my surprise, one of my friends was asked in his interview (he has more than 6 years of experience in Java programming) to write code for getting values from HashMap, Hashtable, ConcurrentHashMap, or TreeMap in Java in at least 4 ways. Just like me he was also surprised by this question but written it. I don't know why exactly someone asks this kind of java interview question to a relatively senior java programmer. Though my closest guess is to verify that whether he is still hands-on with coding in java. 

How to get Key From Value in Hashtable, HashMap in Java? Example

It's not easy to get key from the value in Hashtable or HashMap, as compared to getting value from key because HashMap or Hashtable doesn't enforce one to one mapping between key and value inside Map in Java. in fact, Map allows the same value to be mapped to multiple keys inside HashMap, Hashtable, or any other Map implementation. What you have in your kitty is Hashtable.containsValue(String value) or Hashtable.containsKey(String key) to check whether key or value exists in HashMap or not, but sometimes we want to retrieve a value from Map corresponding to any key and there is no API method to do in Map.

10 Examples of HashSet in Java - Tutorial

HashSet in Java is a collection that implements the Set interface and is backed by a HashMap. Since HashSet uses HashMap internally it provides constant-time performance for operations like add, remove, contains and size give HashMap has distributed elements properly among the buckets. Java HashSet does not guarantee any insertion orders of the set but it allows null elements. HashSet can be used in place of ArrayList to store the object if you require no duplicate and don't care about insertion order.

Difference between HashMap and IdentityHashMap in Java? Example

Hello guys, if you are wondering what is differnece between an HashMap and IdentiyHashMap in Java then you are at right place. IdentityHashMap in Java was added in Java 1.4 but still, it's one of those lesser-known classes in Java. The main difference between IdentityHashMap and HashMap in Java is that IdentityHashMap is a special implementation of Map interface which doesn't use equals() and hashCode() method for comparing objects unlike other implementations of Map e.g. HashMap. Instead, IdentityHashMap uses the equality operator "=="  to compare keys and values in Java which makes it faster compared to HashMap and suitable where you need reference equality check and instead of logical equality.

Difference between bitwise and logical AND, OR Operators in Java? Examples

Java beginners often ask the same type of questions, and of them is what is the difference between & and && operator in Java or the difference between | and || operators? The standard answer to this question is well, the main difference between & and && is that the former is a bitwise operator, and && is a logical operator in Java. That's academic until you clearly explain the difference in working of & and && or | and ||. For absolute beginners, & is used to represent AND logic operation in Java and | is used to represent OR logic operation.

What is NavigableMap in Java ? TreeMap, headMap, tailMap, and subMap Examples

Hello guys, if you are wondering what is NavigableMap and why should Java developer know about it you are at right place. NavigableMap in Java is an extension of SortedMap  like TreeMap which provides convenient navigation methods like lowerKey, floorKey, ceilingKey, and higherKey. NavigableMap is added on Java 1.6 and along with these popular navigation methods it also provides ways to create a Sub Map from existing Map in Java, like headMap whose keys are less than the specified key, tailMap whose keys are greater than specified key and a subMap which strictly contains keys that falls between toKey and fromKey. 

Why use SerialVersionUID inside Serializable class in Java? Example

Serialization and SerialVersionUID always remain a puzzle for many Java developers. I often see questions like what is this SerialVersionUID, or what will happen if I don't declare SerialVersionUID in my Serializable class? Apart from the complexity involved and rare use, one more reason for these questions is Eclipse IDE's warning against the absence of SerialVersionUID e.g. "The Serializable class Customer does not declare a static final SerialVersionUID field of type long". In this article, you will not only learn the basics of Java SerialVersionUID but also its effect during the serialization and de-serialization process. 

Object Oriented Programming Example in Java? Tutorial

I remember when I was doing my engineering, the OOPS concept was in the first semester. Back then it looks like some alien things to me, because I have never done programming and even the smallest program we get to write like checking whether the number is palindrome or not, or printing the Fibonacci series, we never really needed to use OOPS. When needed, I just memorize things and write them down in exams :). That worked, I passed the exam but effectively I didn't learn OOP or Object Oriented Programming on those days.

Difference between Class, Instance and Local variables in Java? Example

There are a lot of differences between instance variable, class variable, and local variable in Java, and knowing them will help you to write correct and bug-free Java programs. Java is a full-featured programming language and provides different kinds of variables like static variables also called Class variable since it belongs to whole Class, non-static also called instance variable and local variables which vary in scope and value. Thank god Java doesn't have any register variable or auto scope like C Programming language, otherwise it would have so much detail to remember. static variables are a common source of error in may multi-threaded java program and does require a bit of carefulness while using it. On the other hand instance, the variable and the local variable have less sharing visibility than a static variable.

Top 10 Hibernate Interview Questions and Answers for Java Developers - 3 to 5 Years Experienced

Hibernate Interview Questions are asked on Java J2EE Interviews, mostly for web-based enterprise application development roles. The success and acceptability of Hibernate framework on the Java world have made it one of the most popular Objects Relational Mapping (ORM) solutions in the Java technology stack. Hibernate frees you from database-specific coding and allows you to focus more on utilizing powerful object-oriented design principles to implement core business logic. By using Hibernate you can switch between databases rather easily and also take advantage of out-of-box caching facilities provided by Hibernate, in terms of second-level cache and query cache.

Difference between Checked vs Unchecked Exception in Java? Example

Checked and Unchecked Exception is two types of Exception exist in Java. Though there is no difference in functionality and you can very achieve the same thing with either checked Exception or Unchecked Exception, there is some difference on exception handling part. In this Java tutorial we will see what is checked and Unchecked Exception in Java, Examples of Checked and Unchecked Exception and most importantly we will learn when to use Checked Exception and when to use Unchecked Exception in Java and lastly we will see the difference between checked and unchecked exception to understand things better. 

[Solved] How to solve java.lang.UnsatisfiedLinkError: no ocijdbc11 in Java with Oracle 11g, 12c, 19c and 21c

"java.lang.unsatisfiedlinkerror no ocijdbc11 in java.library.path" error comes when you try to connect to Oracle 11g database using OCI (thick) driver by using tns name, but the ocijdbc11.dll file is not available in PATH or java.library.path environment variable. ocijdbc11.dll is a native library and if you know Java searches native library in PATH or a location specified by java.library.path system property, if it doesn't find the dll, then it throws java.lang.unsatisfiedlinkerror no ocijdbc11 in java.library.path error. This dll is usually found in C:\Programs\Oracle\ora11g\bin\ocijdbc11.dll, but it could vary depending upon your Oracle installation.

How to fix java.lang.UnsupportedClassVersionError: Bad version number in .class files? Example

How to fix Bad version number in the .class file

"java.lang.UnsupportedClassVersionError: Bad version number in .class file" is a common error in Java programming language which comes when you try to run a Java class file which was compiled by different version of Java compiler than then JRE version you are using to run it. In our last article, we discussed that how to resolve Java.lang.UnSupportedClassVersionError and found that it comes when a major and minor version of the class is not supported by Java virtual machine or JRE running the program. Though "java.lang.UnsupportedClassVersionError: Bad version number in .class file" is a little different than that of its manifestation and Cause, both are related to the mismatch in compiler javac and runtime java version. 

How to Fix Must Override a Superclass Method Error Eclipse IDE Java | @Override annotation with interface methods

One of the annoying error while overriding Java method in Eclipse IDE is must override a superclass method error, This error is quite frequent when importing Java projects and after so long, still I haven't seen any permanent solution to it. Must override a superclass method the error comes in Eclipse if you have Java Class that implements interface and overrides a method from interface and uses @Override annotation. Unfortunately, Eclipse defaults to Java 1.5, which only recognize @Override annotation for the overriding method from the superclass and not from the interface.

How to fix "No compiler is provided in this environment. Perhaps you are running on a JRE rather than a JDK" in Eclipse & Maven?

If you are like many Java developer who uses Maven and Eclipse to build Java project using M2Eclipse plugin, you might have seen this error before. I ran into it recently when I ran the Maven Install command for one of the Java projects, configured as Maven project,  only to realize that Maven builds failed after throwing this error. The main reason for this error is that Maven is not able to find javac (the Java compiler) which is required to compile Java source files. If you remember, the javac command comes in the bin directory of JDK, hence, you need a JDK installation in your local machine to compile the Java project.

How to fix java.sql.SQLException: Invalid column index? Example

"java.sql.SQLException: Invalid column index" is a frequent error while working in Java Database Connectivity (JDBC). As the name suggests "Invalid column index" its related to accessing or setting column in your SQL Query using prepared statement in Java. I have seen "java.sql.SQLException: Invalid column index" coming mostly due to two reason:

1) Setting column data using setXXXX(int coloumIndex) e.g. setInt(0) setString(0)

2) Getting column data using getXXX(int columnIndex) e.g. getInt(0) getString(0)

The most common cause of "java.sql.SQLException: Invalid column index" is a misconception that column index started with "0" like array or String index but that's not true instead column index starts with "1" so whenever you try to get or Set column data with column index "0" you will get "java.sql.SQLException: Invalid column index".

FIX Session is not connecting how to diagnose it? Example Tutorial

In this blog post of the FIX protocol tutorial series I would like to share my experience with connectivity issues around Fix Engines. to exchange messages or say to trade electronically clients connect to the broker using FIX protocol and for that, they use FIX Engine. In FIX protocol connection between two FIX Engines is refereed as FIX Session and we normally say whether FIX Session is connected or not connected. FIX Session normally has their start time, end time, and EOD time (End of day time) also called TradingSession start time, Trading Session End Time, and Trading Session EOD time.

How to empty an ArrayList in Java? clear() vs removeAll() method Example Tutorial

Many times we want to reset an ArrayList for the reusing purpose, by resetting we mean clearing it or removing all elements. There are two ways to reset an ArrayList in Java, by using the clear() method or calling removeAll(). If your ArrayList is small enough like it contains only 10 or 100 elements then you can use any of these two methods without worrying too much, but, if you have a huge list of lots of objects like an ArrayList containing 10M entries, then the choice of clear() vs removeAll() can make a huge difference in the performance of your Java application.

How to loop or Iterate over ArrayList in Java? Iterator, ListItreator, for loop and Enhanced foreach example

Looping ArrayList in Java or Iteration over ArrayList is very similar to a looping Map in Java. In order to loop ArrayList in Java, we can use either foreach loop, simple for loop, or Java Iterator from ArrayList. We have already touched iterating ArrayList in 10 Example of ArrayList in Java and we will see here in detail. We are going to see examples of all three approaches in this ArrayList tutorial and find out which one is clean and the best method of looping ArrayList in Java. Before start writing an example for loop in ArrayList let's think about why do we need to iterate, traverse or loop an ArrayList if it’s based on the index and backed by Array.

Coursera Review - Is the Meta Frontend and Backend Developer Certificates Worth It?

Hello guys, if you want to become a frontend or backend developer in 2022 and looking for a well structured, reputed, and completely online program then Meta's Frontend and Backend developer certificates on Coursera are great place to start with. The Certifications will come from Meta, parent company of Facebook (similar to how the Certificates come from Google in the Google Professional Certificates) and they are taught by expert Software engineers of Meta. This means you will not only learn the latest tech skills which are highly looked after by employers but also you will get a chance to learn from best people in the world. But, what separate this professional certificate on Coursera form others is the access to Meta Job board. 

How to convert a List to Set in Java? ArrayList to HashSet Example

Converting ArrayList to Set in Java means creating a Set implementation like HashSet from an ArrayList full of objects. Before Converting your ArrayList into HashSet do remember that List keeps insertion order and guarantees the same but Set doesn't have such obligation. Also, List allows duplicates but Set doesn't allow any duplicates, which means if you have duplicates in your ArrayList they will be lost when you convert ArrayList to HashSet and that's the reason why the sometimes size of ArrayList doesn't match with the size of HashSet after conversion.

How to become Blockchain Architect in 2023? Is Blockchain Architecture Certification by 101 Blockchains worth it?

Blockchain solutions have been making a lot of noise in the tech space recently for all the right reasons. It comes with the advantage of decentralization, security, and transparency. At the same time, you can also notice the possibility of a growing ecosystem of use cases. A Certified Enterprise Blockchain Architect can serve as a promising asset for enterprises in the present times. How? The work of an architect focuses on designing blockchain solutions by evaluating the requirements of the specific use case.

How to learn Metaverse from scratch? Is Certified Metaverse Professional (CMP) on 101 Blockchains worth it

Is Certified Metaverse Professional (CMP) on 101 Blockchains worth it?
Hello guys, if you want to learn Metaverse in 2022 and wondering how to learn Metaverse then you have come to the right place. Earlier, I have shared best Metaverse online courses and in this article, I am going to review one of the popular Metaverse certification, The certified Metaverse Professional certification from 101 Blockchains, one of the leading portal for Blockchain, Web3, NFT, and Metaverse training. The Metaverse is the next big thing, and you must have heard this a million times, just like many tech enthusiasts. The diverse elements of the metaverse have the potential to grab the attention of every person on the planet. Many big companies have already placed their stakes in the metaverse. 

10 Free Web Development Courses for Beginners in 2023 - Best of Lot

Hello guys, if you want to learn Web Development in 2023 and looking for best free resources like free online courses, tutorials, and books then you have come to the right place. Earlier, I have shared best online courses to learn HTML, CSS, JavaScript, React, Angular, and Node.js and in this article, I am going to share best free online courses to learn Web Development. The article includes free web-dev courses from sites like Udemy and Coursera which anyone can join free to learn essential Web development skills in 2023. But, Before we get to the 7 best free courses that will teach you everything you need to know about web development, let me tell you what it really is.

10 Example of Hashtable in Java – Java Hashtable Tutorial

These Java Hashtable Examples contain some of the frequently used operations on Hashtable in Java. when I discussed throw of How HashMap or Hashtable works in Java I touched based on the inner working of Hashtable, while in this Java Hashtable tutorial we will see some examples of hashtable in Java like checking a key exits in HashMap or not or get all keys and values from HashMap, Iterating on Hashtable keys and values using Enumeration, checking if Hashtable contains a particular key or value, how to copy mappings from a Hashtable to HashMap in Java, etc.

How to use ArrayList in Java? 10 Examples of ArrayList

ArrayList in Java is the most frequently used collection class after HashMap in Java. Java ArrayList represents an automatic re-sizeable array and used in place of the array. Since we can not modify the size of an array after creating it, we prefer to use ArrayList in Java which re-sizes itself automatically once it gets full. ArrayList in Java implements the List interface and allows null. Java ArrayList also maintains the insertion order of elements and allows duplicates opposite to any Set implementation which doesn't allow duplicates. ArrayList supports both the Iterator and ListIterator for iteration but it’s recommended to use ListIterator as it allows the programmer to traverse the list in either direction, modify the list during iteration, and obtain the Iterator's current position in the list.

Top 10 Free Spring Boot and Spring Framework Courses in 2023 - Best of Lot

Hello guys, if you want to learn Spring Framework and Spring Boot in 2023 and looking for free resources like free online courses, tutorials, and books then you have come to the right place. Earlier, I have shared best online courses to learn Spring Framework, Spring MVC, Spring Boot, Spring Security, Spring Data JPA, and Reactive Spring/WebFlux and in this article, I Am going to share best free online courses to learn Spring Framework and Spring boot in depth. But, Before we get to the 10 best free Spring courses that are perfect for beginners, let me tell you more about what the Spring Framework really is.

How to sort ArrayList in Natural and Custom Order in Java - Example Tutorial

Sorting ArrayList in Java is a common task for Java developers and we have touched it while discussing in my last article 10 Examples of  ArrayList in Java and again when we discussed comparator and comparable in Java. In order to sort an ArrayList, we need to use the Collections utility class which contains an overloaded sort() method for sorting different collections and supports different comparators in Java. In this article, we will see how to sort ArrayList in the natural order of elements and then sorting ArrayList in Java with a comparator.

How to find current directory in Java with Example

Hello guys, if you want to find current directory in Java and looking for a simple example then don't worry. Its easy to get current directory in Java by using built-in system property provided by Java environment. Current directory represent here the directory from where "java" command has launched. you can use "user.dir" system property to find current working directory in Java. This article is in continuation of my earlier post on Java e.g. How to load properties file in Java on XML format or How to parse XML files in Java using DOM parser and Why Java doesn’t support multiple inheritance . If you haven’t read them already, You may find them useful and worth reading. By the way here is a quick example of finding current directory in Java:

How to read from and write to a text file in Java - Example Tutorial

Java has excellent support for reading from file and writing to file in Java. In the last post, we have seen how to create files and directories in Java and now we will see how to read content from files in java and how we will write text into file in Java. File provides a persistent solution to Java developers; in almost every Java application you need to store some of the data in persistent may be its user configuration, system configuration or related to state of the application but without persistence, no enterprise Java application can buildup. 

How to append text into File in Java – FileWriter Example

As a Java developer we often need to append text into File in Java instead of creating a new File, for example log files where every message is written into same file or appended at the end of the file. Thankfully Java File API is very rich and it provides several ways to append text into File in Java. Previously we have seen how to create files and directories in Java and how to read and write to a text file in Java and in this Java IO tutorial we will see how to append text into files in Java. We are going to use the standard FileWriter and  BufferedWriter approach to append text to File. One of the key points to remember while using FileWriter in Java is to initialize FileWriter to append text i.e. writing bytes at the end of the File rather than writing at the beginning of the File.

How to Copy a File in Java Program - Example Tutorial

How to copy files in Java from one directory to another is a common requirement, given that there is no direct method in File API for copying files from one location to another. A painful way of copying files is reading from FileInputStream and writing the same data to FileOutputStream to another directory. Though this process works it's pretty raw to work with and the best approach is for anyone to create a library for common File operations like cut, copy, paste, etc. 

How to read File into String in Java 7, 8 with Example

Many times you want to read contents of a file into String, but, unfortunately, it was not a trivial job in Java, at least not until JDK 1.7. In Java 8, you can read a file into String in just one line of code. Prior to the release of new File IO API, you have to write a lot of boilerplate code e.g. open an input stream, convert that input stream into a Reader, and then wrap that into a BufferedReader and so on. Of course, JDK 1.5's Scanner class did provide some breathing space but it was still not as simple as it should be, like in Python or Ruby. By using Java 7 new File API and Java 8's new features like lambda expression and Stream API, Java is now close to Python or other utility languages, when it comes to reading the file into String.

Top 5 Free and Paid OCAJP, OCPJP Mock Exams and Practice questions - (Java Certification)

In order to do well on Java certifications, you need good books and a reasonable number of practice questions before you go for exams. Practice questions and mock exams will help you to assess your topic-wise preparation level and help you to identify your strong and weak areas. Based on the result of the mock exams, you can concentrate on areas where you lack expertise like multi-threading is one of the tricky areas. It will also expose you to exam patterns and different types of questions you can expect in examination like multiple choice questions, rearranging code, fill in the blanks etc. Though I highly recommend commercial exam simulators like Whizlabs and Enthuware, I also suggest you take advantage of many mock questions which are freely available.

How to read a File in One Line in Java? Files.readAllLines() Example Tutorial

Reading a file in Java is not simple, it requires lots of boilerplate code, as we have seen in our earlier example of reading text files. Various things had to be wrapped e.g. a FileInputStream inside a BufferedReader, loops with weird terminating conditions had to be specified, and so forth. From JDK 7 onward,  you can do a lot better. It provides lots of useful classes like Files and Paths to deal with file and their actual path. In this article, we will see how we can read a file in just one line. Of course, your production code won't be like that, especially if you are reading a few gigabytes into memory and want to pay attention to the character set, if you don't specify, by platform's default character encoding will be used.

Java 8 - Stream FlatMap Example - List of Lists to List

The flatmap is an interesting concept of functional programming which allows you to flatten the list or stream apart from transforming it, just like the map does. This means you can use the flatmap to flatten the stream. If you have used the map() function from the Stream class before then you can use it to convert an object of type T to another object of Type S. For example, if you have a list of Authors then you can convert it to a List of books by transforming authors to books. FlatMap extends this idea, it not only transform one object to other it also flattens the list and that's it's very useful where you want to know about a combined data set. 

How to convert java.util.Date to java.sql.Date - JDBC Example

You often need to convert java.util.Date to java.sql.Date if you are storing dates in a database e.g. SQL SERVER or MySQL. Since JDBC has their own data types for date and time e.g. java.sql.Date, java.sql.Time and java.sql.TimeStamp to match with database date, time and date-time types, you cannot pass a java.util.Date directly. All methods which are supposed to store dates e.g. setDate(paramName, paramValue) expects java.sql.Date, so it becomes essential to know how to convert java.util.Date to java.sql.Date in JDBC. You would be surprised to know that java.sql.Date is a subclass of java.util.Date and all it does is suppress or remove time-related fields from java.util.Date.

Educative Review - Is Grokking Advanced System Design Interview Course Worth it?

Before I give my review of Educative's Grokking Advanced System Design Interview, let me tell you a little bit more about this course so that we are on the same page. As you must already know if you have ever sat for a software engineering interview, system design questions are an integral part of the process. System design plays a very important part as it is considered more important than solving coding problems. And in order to impress your potential employers, you have to be able to show your real design skills and convince them that you are able to work with complex design systems.

How to convert String to Date in Java - SimpleDateFormat Example

Hello Java developers, you may know that SimpleDateFormat in Java can be used to convert String to Date in Java. java.text.SimpleDateFormat is an implementation of DateFormat which defines a date pattern and can convert a particular String that follows that pattern into Date in Java. This is the second part of the article on java.util.Date and String in Java. In the first part, we have seen How to convert Date to String in Java. SimpleDateFormat accepts a String in any date format e.g. yyyyMMdd is a date pattern and  20220924 is a String in that format. Now you want to create a java.util.Date object from this String.

How to Convert Date to String in Java with Example

As a Java developer we often need to convert java.util.Date or LocalDate to String in Java for  displaying purpose or sending Date as String in JSON or XML messages and that's where having a agree upon Date Format is very important. It easily allows you to convert your Date as String and pass between two System. I need it that while working on displaying date in my application and then I thought about this article to list down various way of converting this in various ways after some reading I found that SimpleDateFormat makes this quite easy. 

How to convert Date to LocalDate and LocalDateTime in Java 8 - Example Tutorial

The easiest way to convert a java.util.Date to java.time.LocalDate is via Instant, which is the equivalent class of java.util.Date in JDK 8. You can first convert util Date to Instant and then create a LocalDateTime object from that instant at your default timezone. Once you have an instant of LocalDateTime, you can easily convert that to LocalDate or LocalTime in Java. If you are not living under the rock in the last two years that its 2016 and Java 8 has been around for more than 2 years, 18th March 2014 Java SE 8 GA happened.

17 Examples of Calendar and Date in Java - Tutorial

The java.util.Calendar class was added in Java on JDK 1.4 in an attempt to fix some flaws of the java.util.Date class. It did make some tasks simpler, e.g. create an arbitrary date comes easier using the new GregorianCalendar(2016, Calendar.JUNE, 11) constructor, as opposed to the Date class where the year starts from 1900 and the Month was starting from zero. It didn't solve all the problems like mutability and thread-safety of Date class still remains, but it does make life easier at that time. Now with Java 8 everything related to Date and Time has become super easy and consistent but unfortunately, it will take another 5 to 10 years before the older version of Java goes away. Don't believe me, there are still applications running on JDK 1.5 which was released 12 years ago. The bottom line is it's still important to know about the Date and Calendar in Java.

10 Examples of Optional in Java 8

Null is bad, it can crash your program. Even its creator called it a billion-dollar mistake hence you should always try to avoid using nulls whenever you can. For example, you should not return a null String when you can return an empty String, similarly never return null collections when you can return an empty collection. I have shared many such tips in my earlier article, 10 tips to avoid NullPointerException and my reader liked that a lot. But, I wrote that article a couple of years ago when Java 8 was not around and there was no Optional, a new way to avoid NullPointerException in Java, but, things have changed now.

How to find the largest and smallest number in given Array in Java? Example Tutorial

Hello guys, today I am going to discuss one of the frequently asked programming interview questions to find the largest and smallest number from an integer array. This question is commonly asked on telephonic interviews and the first round for screening candidates. This coding problem is in the same league of other frequently asked algorithmic questions like Fibonacci, Palindrome, Prime, and Power of two checks. They are easy but you will find them difficult during the interview because of the pressure, particularly if you have not solved them before. Sometimes even if you have solved the problem one time, you tend to do mistakes because you haven't understood them properly. So, always take your time to understand the question.

How to Implement Stack Data Structure in Java? Example Tutorial

The stack is one of the popular data structures which supports LIFO (Last In First OUT) operation. Due to the LIFO advantage, you can use a stack data structure to convert a recursive algorithm to an iterative one. The stack data structure is very easy to implement using an array or linked list, but you don't have to implement it on your own because Java already provides a Stack implementation in java.util.Stack class. This class is a subclass of the Vector class and you should use it whenever you need Stack for your production code, there is no point in inventing the wheel again when the focus is on developing your application.

Review - Is Metaverse Professional Certification on 101 Blockchains worth it?

The metaverse is the next big thing, and you must have heard this a million times, just like many tech enthusiasts. The diverse elements of the metaverse have the potential to grab the attention of every person on the planet. Many big companies have already placed their stakes in the metaverse. Therefore, it is quite clear that a Certified Metaverse Professional certification would be helpful in terms of career development. Interestingly, the opportunities for career development in the metaverse have been doubling in recent times. The following discussion helps you find whether the CMP certification by 101 Blockchains is the best choice in metaverse certifications for you.

10 Difference between Java and JavaScript for Programmers

Programmers, developers, and internet users have always been confused between Java and JavaScript.  Many people still think that JavaScript is part of the Java platform, which is not true. In truth, JavaScript has nothing to do with Java, the only common thing between them is the word "Java", much like in Car and Carpet, or Grape and Grapefruit. JavaScript is a client-side scripting language for HTML, developed by Netscape, Inc, while Java is a programming language, developed by Sun Microsystems. James Gosling is the Inventor of Java, popularly known as the father of Java. 

Top 20 jQuery Interview Questions and Answers for 1 to 3 Years Experienced

Without a doubt, jQuery has given a much-needed boost to JavaScript, a language so useful but equally underrated at times. Before jQuery comes into the picture, we used to write lengthy JavaScript code not just for bigger but even for smaller functions. Those codes were at times both difficult to read and maintain. Having written JavaScript before using this excellent library, I realized the true power of jQuery, just after using it for a month. Given its huge popularity, jQuery interview questions are increasingly asked in any web developer interview, not just beginners but also experienced developers, including HTML and JavaScript.

How to get current URL, parameters and Hash tag using jQuery and JavaScript? Example

While dealing with the current URL, many times you want to know what is the current URL path, What are the parameters, and what is the hashtag on the URL. The hashtag is pretty important if you are implementing a tab structure using HTML and JQuery. To avoid confusion, let's take an example of a URL: http://javarevisited.blogspot.com/2013/01/top-5-java-programming-books-best-good.html#ixzz2PGmDFlPd, in this example ixzz2PGmDFlPd, is a hashtag. Now, both JavaScript and JQuery provide a convenient way to retrieve the current URL in the form of window.location object. You can use various properties of the window.location JavaScript object like the window.location.href to get complete URL, window.location.pathname to get the current path, and window.location.hash to get a hashtag from current URL.

Top 10 Free NFT (Non Fungible Tokens) Courses for Beginners in 2023 - Best of Lot

Hello guys, if you want to learn about NFTs or Non Fungible Tokens and looking for best free online courses then you have come to the right place. Earlier, I have shared best paid NFT courses and in this article, I am going to share best free NFT courses for beginners, Bu, before we get to the 10 best free NFT courses that will teach you everything you need to know about this exciting new technology, let me tell you what it really is. NFTs, also known as Non-Fungible Tokens, are basically unique cryptographic tokens. These tokens exist in a blockchain, which means that they cannot be replicated. Each NFT has a unique identification and metadata.