How to use Queue Interface in Java? Example Tutorial

The JDK provides an implementation of several data structures in the Java collection framework like ArrayList is a dynamic array, LinkedList represents a linked list, HashMap represents a hash table data structure, and Queue interface represent queue data structure. Btw, If you are not familiar with data structure itself, then you can also see Introduction to Data Structures & Algorithms in Java, an excellent course to start with the essential data structure in Java. The Queue data structure allows you to process elements in the first in first out order, and that's why it is also known as a FIFO data structure.

How to Convert Date to LocalDate in Java 8 - Example Tutorial

Hello guys, if you want to learn how to convert old Date to new LocalDate in Java 8 then you have come to the right place. Earlier, I have shared 10 examples of LocalDate in Java 8, and in this article, I am going to teach you how to convert Date to LocalDate in Java. you may know that JDK 8 introduced the new Date and Time API, which has got a new set of shiny date classes like LocalDate, LocalTime, etc, but you still have a lot of code written against java.util.Date? In order to work with that code, you should know how to convert java.util.Date to java.util.LocalDate in Java.

Top 6 Free Courses to learn PHP and MySQL in 2022 [Updated] - Best of lot

If you want to build web applications quickly like overnight or over the weekend, then PHP and MySQL are the right choices and because of this power, they are also the best language for freelancing and startups where a quick turnaround time is required. PHP and MySQL are incredibly powerful open source technologies that allow programmers and web developers to create functional websites and apps that go way beyond basic HTML. PHP is specially designed to generate interactive and dynamic websites and is also known as the server-side scripting language, while MySQL is one of the leading relational databases along with Oracle and Microsoft SQL Server.

How to Search an Element in Java Array with Example? ArrayUtils Tutorial

find an index of the object in Array

While programming in Java, many times we need to check if a String array contains a particular String or an integer array contains a number or not. Though array is an object in Java but it does not provide any convenient method to perform searching elements or finding elements. Sometimes you even need an index of an item stored in Array, unfortunately, Java API does not provide any direct method. Thanks to Open Source Apache Commons provides a utility class called ArrayUtils which allows you to check for an Item in Array, find its index in the array, find its lastIndex in Array and perform several other common operations.

Top 8 Free Courses to Learn Web Design in 2022 - Best of Lot

Hello guys, if you want to become a web designer and look for free online courses to learn web design in 2022, you have come to the right place. In the past, I have shared the best free online resources to learn key web development skills like HTML, CSS, JavaScript, Bootstrap, and today, I am going to share the best free resources to learn web design and development. These free courses have been created by expert instructors like Jonas Schmedtmann, and they are from websites like Udemy, Coursera, and edX. You can use these free online courses to learn these valuable skills and become a web designer and developer.

[Solved] How to Find Repeated Characters in a given String with count in Java? Example

This is another interesting coding problem or programming exercise for beginner programmers. How do you find repeated or duplicate characters in a given String and their count? You can solve this coding problem in any programming language of your choice like Java, Python, Ruby, or even JavaScript. I'll explain the logic and solution which is easy to implement in the above programming languages and I'll provide code in Java, which is my favorite programming language. In order to solve this problem, You need to first check if a String contains any duplicate characters or not, and then if it contains any duplicate letters then find out how many times they appear in the given input String.

Top 5 Free Courses to learn Django for Beginners in 2022- Best of Lot

Hello guys, if you want to learn Django and looking for some free online Django courses to start with, then you have come to the right place. In the past, I have shared the best Python courses and best Django courses, and today, I am going to share free Django courses you can join online to learn this useful full-stack Python framework. There is no doubt that Python is the king of a Programming language at this moment, and one main reason for that is the huge number of powerful frameworks and libraries it has for different purposes like automation, data science, machine learning, scripting, data analysis, and Web development is no different.

5 Best Free Flutter Courses Online for Beginners in 2022 - Best of Lot

Hello guys, if you want to learn Flutter for App development in 2022 and looking for free Flutter courses then you have come to the right place. In the past, I have shared the best Flutter Courses but many of my readers asked for free online Flutter courses to start with and that's how this article is born. In this article, you will find a list of free online courses to learn Flutter from the best instructor on the internet. These courses cover Flutter as well as Dart, in case you don't know, Dart is a programming language and Flutter is the framework for creating mobile and web apps using Dart.

[Solved] How to solve a coin change problem in Java? Example

The coin change problem is one of the popular coding interview question and knowing how to solve this problem can help you during coding interview. It's also useful to learn a couple of tricks and data structure. This problem somewhat has to do with arrays, so we shall be discussing what an array is, But before we dive into this. we need to understand the problem. We are about to solve a coin problem by determining how many possible ways an amount can be paid. Suppose, Mary is a Businesswoman who deals with coin change.

7 Best Online Courses to Learn Go or Golang in 2022 - Best of Lot

Hello guys, if you want to learn the Go programming language in 2022 and look for the best Golang online courses, you have come to the right place. Earlier, I shared the best JavaScript Courses, and today, I will share the best online lessons to learn one of the modern programming languages called Go or Golang. This popular, next-generation, highly efficient programming language is created by none other than Google, creator of Angular, Android, Flutter, and Dart, to make their software development process smoother and better.

How to print a Right Triangle Pattern in Java - Example Tutorial

Hello Java Programmers, here we are back again with a pattern based exercise. In the past, I have shared article on how to print pyramid pattern of stars in Java, Left Triangle Star Pattern, and Pyramid pattern of alphabets, and in this article, I will show you how to print a right triangle start pattern in Java. Pattern based exercises are great way to learn programming and coding as it encourage you to use logic and use essential programming constructs like loop and arrays.

Difference Between Iterator and Enumeration In Java

What is the difference between Iterator and Enumeration in Java is one of the oldest core Java Interview Questions. While I haven't seen this question for a long time, I still think its an important concept to know and remember for Java developers, especially those who are tasked to work in existing project which may be using Enumeration. The Iterator and Enumeration are two interfaces in Java and used for traversing in java collection we found these two interface in the java.util package .whenever we go for an interview if interviewer goes in collection topic he will often ask the difference between this two .so let's see one by one difference between this two and compare which is used when and which one is better.

[Solved] How to convert Decimal to Binary Number in Java? Example Tutorial

Hello guys, how are you doing? I have been sharing a lot of programming interview questions and coding problems for practice in this blog. Earlier, I have shared 21 String programing questions, 100+ data structure questions, and 20 System design questions and this week's programming exercise is to write a program to convert a decimal number to binary in Java. It's a simple exercise for beginners who have just started learning the Java programming language. Decimal numbers are base 10 numbers, which means there are exactly 10 digits to represent a number, starting from 0 to 9, on the other hand, the binary number system has just two digits 0 and 1, which is known as bits.

[Solved] How to find all pairs which add up to a given value in an Integer Array in Java? Example

Hello guys, if you are preparing for programming job interview then you know that the problem of finding all pairs which adds up to a given value in a give array is a popular array based coding question. This question is also known as Two sum problem because you need to find pair of two elements in the array whose sum is equal to given number. For example, you have given an array of integers with values {1, 2, 3, 4, 5, 6} and you need to find all the pairs whose sum is equal to 5. In this case, there are two such pairs (1, 4) and (2, 3) so your program needs to print them into console.

3 Difference between multi-threading and multitasking? [Answered]

Hello guys, what is the difference between multithreading and multitasking is a common Java interview questions. If you are also wondering what it the real difference between them as they sound similar the continue reading this article and you will find the answer. In the programming world, there are two main ways to improve the throughput of a program, by using multi-threading and by using multitasking. Both take advantage of parallelism to efficiently utilize the immense power of the CPU and improve the throughput of your program. Actually, multi-threading is nothing but thread-based multitasking.

How to convert String to Date in Java? Example Tutorial

Hello guys, if you are wondering how to convert a String to Date object in Java then you have come to the right place. Data type conversion is one of the most common tasks in programming and every Java programmer must know how to convert one type to another type. There are many times when you will be required to convert a String to LocalDate or java.util.Date object mostly in a different format like dd-MM-yy or yyyy-MM-dd or simply yyyy MM dd. For example, clients pass dates as String to the Server or sometimes we read Date related data from CSV file. Java provides API for parsing String to date using DateFormat class, though Java's Date and Time API is severely criticized, it is also the most used Date and Time format solution.

10 Best Udemy Courses of Colt Steele for Web Developers in 2022

Before we get to the 10 best Udemy courses of Colt Steele, let me tell you who the man really is. Colt Steele is one of the most popular and highly-rated instructors on the Udemy platform. He is also a highly-decorated professional developer with a serious love for teaching. Colt Steele has spent the last few years teaching normal people to program at two different impressive boot camps. He has helped hundreds of people become professional software developers and change their lives. His students now work in companies like Google, Salesforce, and Square. Impressive, right?

What is difference between start and run method of Thread in Java? Answer

Hello guys, what is the difference between calling start() vs run() method in Java multithreading is a popular core Java interview questions and if you are wondering the subtle difference between two then you have come to the right place. In this article, I will answer this question and show you an example as well. If you remember, a Thread is started in Java by calling the start() method of java.lang.Thread class, but if you learn more you will find out that the start() method internally calls the run() method of the Runnable interface to execute the code specified in the run() method in a separate thread.

How to delete multiple elements from a LinkedList in Java? Bulk Remove Example

Hello guys, if you are looking for an easy way to remove a sub set of elements from a LinkedList in Java then you have come to the right place. In the past, I have shown you how to sort a LinkedList in Java and how to create your own linked list implementation in Java and in this article, I am going to introduce you with an interesting method which can be used to delete a portion of LinkedList in Java in shot. Yes, there is a method exists but not many Java developer knows about it. The method is called subList() and you can use this method with clear method in Java to delete a portion of linked list in one shot.

Difference between Self and Equi Join in SQL - INNER Join example MySQL

The main difference between Self Join and Equi Join is that In Self Join we join one table to itself rather than joining two tables. Both Self Join and Equi Join are types of INNER Join in SQL, but there is a subtle difference between the two. Any INNER Join with equal as join predicate is known as Equi Join. SQL Joins are the fundamental concept of SQL similar to correlated and noncorrelated subqueries or using group by clause and a good understanding of various types of SQL join is a must for any programmer.

Difference between fixed vs cached thread pool in Java

There are mainly two types of thread pools provided by Java's Executor framework, one is fixed thread pool, which starts with fixed number of threads and other is cached thread pool which creates more threads if initial number of thread is not able to do the job. The newCachedThreadPool() method is used to create a cached pool, while newFixedThreadPool() is used to construct a thread of fixed size. Cached thread pool executes each task as soon as they are submitted, using an existing thread if its idle or creating new threads otherwise, while in case of fixed thread pool, if more tasks are submitted then idle threads then those task are put into a queue and later executed once any other task has finished.

Top 5 Books to Learn Web Development for Beginners in 2022 - Best of Lot

Having a career in web development can be a fun and fabulous experience. There are a lot of online videos on YouTube or paid courses to teach you this field, but not all people are fan of videos and many of us like to learn from books. So I’ve collected some of the best web development books to help you learn this field in a small amount of time and even maybe get a real job after completing them. While I also advocate a hybrid approach where you can start with these free web development online courses first to learn the 20% stuff which are used 80% of time and then move to books, but its totally up to you.

10 Best Udemy Courses of Tim Buchalaka for Java and Python Programmers

Hello guys if you are looking for best Udemy courses for Java developers, mostly from Tim Buchalaka then you have come to the right place. For those of you who don't know, Tim Buchalaka is a highly-experienced software developer. During his long glittering career, he has worked for a lot of major companies like Fujitsu, Mitsubishi, and Saab. Tim Buchalaka's amazing video lectures have been used to train software developers in major companies like Mercedes-Benz, PayPal, VW, Pitney Bowers, IBM, and T-Mobile. What sets Tim apart from loads of other instructors is the fact that most of those instructors have never been professional programmers. They also cannot boast about a distinguished professional development career like him.

2 Ways to solve FizzBuzz in Java? [Example]

Hello guys, if you are learning to code or preparing for interviews and looking how to solve the FizzBuzz problem in Java then you have come to the right place. Earlier, I have shared 75 programming exercises and in this article, I will teach you how to solve the FizzBuzz problem in Java. FizzBuzz is one of the most frequently asked questions on programming interviews and used to filter candidates on Coding interviews who can't code. It looks extremely simple but it's tricky for those programmers or coders who struggle to structure their code or lack the ability to convert a simple algorithm into code.

Difference between HashMap vs TreeMap vs LinkedHashMap in Java

Though all three classes like HashMap, LinkedHashMap and TreeMap are implementation of java.util.Map interface, there is some functional difference between them. Perhaps most notable difference between them comes from their iteration order. HashMap makes absolute no guarantee about in which order you can iterate their keys, any application depending upon iteration order of HashMap is fragile, because it can change anytime. Infact, in Java 7, iteration order of HashMap is different than Java 6. On the other hand TreeMap is a SoretedMap and keeps their key in particular sorted order, enforced by either natural order of keys or Comparator instance provided during construction of TreeMap.

Top 5 Books To Learn Machine Learning and AI in 2022

Hello guys if you want to learn Machine Learning and Artificial Intelligence and looking for best books then you have come to the right place. Earlier, I have shared best Machine learning and AI courses and today, I am going to share best books you can read to learn Machine Learning and AI in 2022. Machine learning is considered a subset of artificial intelligence. They are used a lot in our daily lives, like in google, to give you the search results to the YouTube recommendation videos and amazon recommendations for shopping. It is also used for self-driving cars and googles assistance. Basically, it will take the data, learn from it, and give you the result from unseen data later.

How to Find Highest Repeating Word from a File in Java [Word Count Solution]

Hello guys, if you are looking for a Java program to print the word and their count from a given file then you have come to the right place. Earlier, I have shared 100+ Data Strucutre and Algorithms Problems from interviews and in this article, I will show you how to find worlds and their count from a given file in Java. How to find the word and their count from a text file is another frequently asked coding question from Java interviews. The logic to solve this problem is similar to what we have seen in how to find duplicate words in a String, where we iterate through string and store word and their count on a hash table and increment them whenever we encounter the same word.

10 Best Udemy Courses Of Rob Percival to Learn Python, JavaScript and Tech skills

Helo guys, if you are looking for best online courses by Rob Percvial, one of the Udemy's top instructor to learn web development, Python, JavaScript, and Node.js then you have come to the right place. In the past, I have shared best online courses by Jose Portilla, Stephen Grider, Maximillian SchwarzMuller, Stephane Maarek and Brad Traversy and in this article, I am going to share best online course by Ro Percival, one of the top Udemy instructor and my favorite. But, before we start with the 10 best Udemy courses from Rob Percival, let me tell you who Rob is.

How to Check if Given Number is Prime in Java - With Example

Hello guys, today, we are going to discuss one of the most common programming exercises for beginners is, write a program to check if a given number is prime or not? There are many ways to check if a number is prime or not, but the most common of them is the trial division, which is what we will see in this tutorial. In my opinion, these kinds of programs are their first steps towards algorithmic understanding. You first come up with a solution, which is driven by the fact that prime numbers are natural numbers, that are not divisible by any positive number other than 1 and themselves. Then, you write a for loop to check every number, starting from 1 to a given number, to see if the given number is divisible by any positive number or not. This leads you to the solution.

What is window function in SQL with Examples? How and when to use them?

Hello folks, if you are wondering what is window function and what problem does it solve then you have to the right place. In this article, I would be explaining the windows functions with examples, how it works, and when you need to use it. Firstly what is a Window Function in SQL? A window function performs a calculation across a set of table rows that are similarly related to the current row. The current row is the row in which function evaluation occurs. This is comparable to the type of calculation that can be done with an aggregate function. But unlike regular aggregate functions like sum, avg, max, and min, that perform operations on an entire table.

[Solved] How to Find 2 Largest Number from Integer Array in Java with Example

Hello guys, I have been sharing a lot of Programming interview questions and coding problems to learn programming better which is appreciated by you guys. In this post, I have come with other simple programming problems for Java beginners. I love to share short programming problems because they help in developing programming sense. Many people will argue against simple problems like prime numbers, palindrome, and factorial, but I really find them useful, especially for beginners. A beginner is far away to solve a complex data structure problem or even more complex problems like those that appear in TopCoder or other programming sites. Programmers learn gradually and they need the joy of doing something and seeing results much quicker than any other. Small success motivates them.

10 Best Udemy Courses of Stephen Grider

Hello guys, if you are looking to learn web development or app development then there is a good chance that you may heard about Stephen Grider, one of the best Udemy instructor when it comes to teaching web development technologies. In the past, I have shared best online courses by Jose Portilla, Maximillian SchwarzMuller, Stephane Maarek and Brad Traversy and in this article, I am going to share best online course by Stephen Grider. But, First things first. before I tell you about the 10 best Udemy courses of Stephen Grider, let me tell you who the man really is.

3 Examples to convert a Map to List in Java 8 - Example Tutorial

Hello guys, when you convert a Map to List in Java 8 or before, you have three choices like you can get a list of keys from Map, a List of values from Map, or a List of entries from Map, which encapsulates both keys and values. The API doesn't provide these methods because Map doesn't guarantee any order and the List interface guarantees ordering, like insertion order. Hence, JDK API provides an equivalent method to convert a Map to Set, like keySet() will return a set of keys and entrySet() will return a set of entries.

Java 8 Predicate and Lambda Expression Example

Hello guys, if you want to learn about Predicates in Java 8 and looking for examples then you have come to the right place. In the past, I have explained key Java 8 concepts and classes like Stream, Optional, Collectors etc and we have seen how to use those functional methods like map, filter, and flatmap and in this article, I will show you how to use Predicates in Java 8 with Lambda expression. If you don't know Predicate is a functional interface in Java. A functional interface is nothing but a function with one abstract method or annotated by @FunctionalInterface annotation. Predicate is a functional interface with a function which accepts an object and return Boolean.

[Solved] How to Check If a Given String has No Duplicate Characters in Java? Unique Example

Hello guys, if you are looking to solve the classic problem "checking if a String has all Unique characters" or not then you have come to the right place. Earlier, I have shown you how to reverse String in place, and in this article, I will show you how to check for unique and duplicate characters in String. You need to write a program to determine if a given string has all unique characters or not. For example input= "Java" then your function should return false because all characters are not unique, and if the input is "Python" then your program should return true because all characters in Python are unique.

How to Find Greatest Common Divisor of two numbers in Java - [ Euclid's algorithm GCD Example]

How to find the Greatest Common Divisor of two numbers in Java

Simple Java program to find GCD (Greatest Common Divisor) or GCF (Greatest Common Factor) or HCF (Highest common factor). The GCD of two numbers is the largest positive integer that divides both the numbers fully i.e. without any remainder. There are multiple methods to find GCD, GDF, or HCF of two numbers but Euclid's algorithm is very popular and easy to understand, of course, only if you understand how recursion works. Euclid's algorithm is an efficient way to find the GCD of two numbers and it's pretty easy to implement using recursion in the Java program. According to Euclid's method GCD of two numbers, a, b is equal to GCD(b, a mod b) and GCD(a, 0) = a.

How to Convert a Stream to List, Set, and Map in Java? Example Tutorial

Hello guys, if you are wondering how to convert a Java Stream to Java Collections like List, Set and Map then you have come to the right place. Earlier, I have shared free Java Courses for beginners and in this article, I am going to share examples to convert Stream to ArrayList, LinkedList, HashSet, TreeSet, LinkedHashSet, TreeMap, HashMap, and ConcurrentHashMap in Java. These are easy-to-follow examples and suitable for both beginners and experienced Java programmers. In Java 8, Stream is one of the most important classes as it allows a lot of useful functional operations like filter, map, flatmap, etc on a collection of objects. Hence, going forward converting a Collection to Stream, performing operations, and then converting the result back to different Collection classes like List, Set, and Map will be a common task.

How to solve Two Sum Array Problem in Java? Example

Hello guys, if you have been solving data structure and algorithms problems or been through a couple of coding interviews then you might be familiar with the classical "Two Sum" problem. It's one of the classical coding problems of finding two numbers in a given array whose sum is equal to a given target number. It's a good problem to learn how array data structure works and programming basics like loops, conditionals, and operators. It's also good for developing your problem-solving skills and coding sense, which will help you in the long run. This is also a popular Leetcode problem and is commonly asked in coding interviews to both beginners and intermediate programmers.

How to convert String ArrayList to Array in Java? Example

Converting String ArrayList into String array is very common programming task in Java. you often need to convert Array to Array List in Java and vice-versa. In this Java program, we will How to convert String ArrayList to String array. This is also a common programming exercise which is asked too many Java programmers in various Java related courses. It’s also worth noting that ArrayList in Java is internally backed by array and Array in Java are objects much like String which is also an Object in Java.

Top 5 books to Learn AWS in 2022 - best of Lot

Cloud services have become a trend in recent years. More and more organizations are moving to cloud services. Amazon Web Services, commonly knowns as AWS is by far the most popular cloud service.

AWS is an on-demand pay-as-you-go pricing service. It offers several products in various domains such as compute and networking services, storage and content delivery services, security and identity services, database services, analytics services, application services, and management tools. Moreover, understanding AWS is easier as compared to other services. It is very user-friendly.

It is worth learning AWS. There are many job opportunities in the market. AWS can be learned from various resources such as the internet and books. While the internet can give better exposure, books are a better option if you want to dive deep into the concepts. In this article, we will list the top five books to learn Amazon Web Services.

5 Best Books to learn AWS And Cloud Computing in 2022

Without wasting anymore of your time, here is a list of best books to learn AWS in 2022

1. Amazon Web Services in Action

This book is written by Andreas Wittig and Michael Wittig who migrated the first bank of Germany to AWS in 2013. It is one of the finest books for learning AWS. In this book, the authors covered all the essential AWS services focusing on security, automation, scalability, and high availability.

The second edition of the book includes all the latest AWS additions such as serverless infrastructure with AWS Lambda, in-memory storage with ElastiCache, and sharing data with EFS.

The book is for mid-level developers and DevOps.

3. Amazon Web Services Bootcamp

Written by Sunil Gulabani, the Amazon Web Services Bootcamp: Develop a scalable, reliable, and highly available cloud environment with AWS book focuses on building and managing highly reliable and scalable applications and services on AWS.

It includes all the essential skills to design, deploy, and manage applications and services on the AWS. The book also contains easy-to-follow, hands-on steps, recommendations, and tips.

The book is for IT professionals with basic knowledge of the cloud and AWS (optional).

4. AWS: The Ultimate Guide From Beginners To Advanced

The latest edition of AWS: The Ultimate Guide From Beginners To Advanced For The Amazon Web Services (2020 Edition) book by Theo H. King will teach you all the essentials of AWS. This book starts from the very basics of AWS and then gradually moves to the advanced topics.

The major topics covered in this book are using development tools of AWS for your advantages, upgrading outsourcing, implementing AWS technologies, and many more.

This book is for IT professionals with basic knowledge of the cloud (optional).

4. Learning Amazon Web Services (AWS): A Hands-On Guide to the Fundamentals of AWS Cloud

This book is written by Mark Wilkins who is a top AWS trainer and evangelist. In this book, you will find every essential concept that is required to master AWS. It has hands-on practices that will help you understand Amazon Web Services in real-time. The author tries to present AWS as a big picture covering AWS fundamentals.

This book is for those developers who want to understand AWS with hands-on practices.

5. Machine Learning in the AWS Cloud: Add Intelligence to Applications with Amazon SageMaker and Amazon Rekognition

Machine learning is another powerful technology. It can be used with AWS and this book is for those who want to use machine learning with AWS. Authored by Abhishek Mishra, this book not only covers the essentials of Amazon Web Services, but also the essentials and fundamentals of machine learning. The book is divided into two parts - part one covers machine learning while part two covers the machine learning services of AWS.

This book is for those who want to learn the machine learning services of AWS.

That's all about the best books to learn AWS for Beginners in 2022. So as mentioned earlier, the AWS can be learned from various sources but books are a better choice for diving in depth. In this article, we listed the top five books that will help you understand and learn Amazon Web Services. Almost every book mentioned in this article requires no prior knowledge of AWS. Go through the description and choose accordingly.

How to calculate sum of all numbers in a given array in Java [Example]

Hello guys, if you are thinking about how to calculate the sum of all numbers in a given integer array then you have come to the right place. Earlier, I have shared 75 programming questions from the interview and in today's coding problem, you will learn how to write a program to calculate the sum of array elements in Java. As part of this coding problem, you need to write a method that will accept an integer array and it should return the total sum of all the elements. The array could contain both positive and negative numbers but only decimal numbers are allowed.

How to check if a Number is Power of Two in Java? [Bitwise AND Example]

Hello guys, if you are thinking about how to check if a given number is a power of two without using an arithmetic operator like division then you have come to the right place. In Java, you can use bitwise operators like bitwise AND check if a given number if the power of two or if the given number is even or odd. In this Java Programming tutorial, you will learn how to check if the number is the Power of two using a bitwise operator. The main purpose of this program is to teach you how to use bit-wise operators like bitwise AND (&) in Java. A number is said to be the power of two if all its prime factors are 2, but in the binary world, things work a little differently.

[Solved] 2 Ways to Find Duplicate Elements in a given Array in Java - Example

Hello guys, today, you will learn how to solve another popular coding problem. You have given an array of objects, which could be an array of integers and or an array of Strings or any object which implements the Comparable interface. How would you find duplicate elements from an array? Can you solve this problem in O(n) complexity? This is actually one of the frequently asked coding questions from Java interviews. There are multiple ways to solve this problem, and you will learn two popular ways here, first the brute force way, which involves comparing each element with every other element, and other which uses a hash table-like data structure to reduce the time complexity of the problem from quadratic to linear, of course by trading off some space complexity.

Top 5 Practice Tests for Google Cloud Professional Cloud Architect Certification Exam

If you are looking for any exam courses to values your skills in the Google Cloud Professional Cloud Architect certification then you are in the right place. Clicking on this article link shows that you are very curious to study more about Google Cloud Professional Cloud Architect certification and as well as taking and succeed in the exam to get your Google Cloud Professional Cloud Architect certification.

Top 10 C++ Interview Questions with Answers for 1 to 2 years Experienced

Today, for a change I am not sharing any Java interview questions, but I am sharing a few C++ interview questions. There is a good demand for developers who know both Java and C++, particularly in the investment banking domain, as a lot of high-performance applications like client connectivity, exchange connectivity, and order management systems (OMS) are written in C++. If you know both Java and C++ then you have a great chance to get a job in big investment banks like Barclays, Nomura, Deutsche Bank, and other Wall Street Firms.

[Solved] 3 Examples to reverse an Array in Java - Example Tutorial

Hello guys, today we are going to see another common coding question from interviews - how do you reverse an array in Java? This is a popular array-based coding problem and often asked programmers during the first few rounds of interviews to check if they can code or not. Well, there are multiple ways to solve this problem and we will see three common ways to ever an array in Java. This method applies to all kinds of arrays like string array or integer array or even with arrays of objects because it's not focused on data types. The first way to reverse an array is by reversing it in a brute force way, without using any additional data structure or library method.

Top 50 Garbage Collection and Java Performance Interview Questions and Answers

Hello Java Developers, If you have gone through any Java Developer interview, particularly for a senior developer role then you know that a good knowledge of JVM internals and Garbage collection is important. Even though Java and JVM take care of memory management for you, bad code can still cause memory leaks and performance issues. For example, if you are creating millions of objects in a loop or keeping an un-intended reference of dead objects then you are putting additional strain on the Garbage collector and creating a memory leak in your application. You cannot blame Java and JVM for that and the only way to avoid such errors is to know about how Garbage collection works.

Top 5 courses for Google Cloud Professional Network Engineer Certification in 2022

Networking is an essential aspect of any cloud platform. The individual responsible for handling the networks should have a proper understanding of networking fundamentals as well as enough experience in networking. The cloud network engineer at Google is responsible for implementing and managing the network architectures of the platform. The professionals should have hands-on experience of working with the Google cloud platform for at least one year.

Spring HelloWorld Example in Java using Annotation and Autowiring

Spring framework has gone a couple of releases since I last share the Spring hello world example with XML configuration. In this article, I am going to explain to you how to create a Spring hello world example with Spring 4.2 release and by using Annotation for dependency injection and autowiring. So no more XML files to specify bean dependencies. It's a simple program that shows how you can use the Spring framework to create Services that are loosely coupled. The example will show you the basic concept of dependency injection by creating a simple Java application that greets the user.

What is ContextLoaderListener in Spring MVC? Example

The ContextLoaderListner is one of the essential components of the Spring MVC framework, probably the most important after the DispatcherServlet itself. It is used to create the root context and responsible for loading beans, which are shared by multiple DispatcherServlet like beans related to the service layer and data access layer. In general, When you develop Spring MVC based web applications and also using Spring in the services layer, you need to provide two application-contexts. The first one is configured using ContextLoaderListener, and the other is set using DispatcherServlet. The DispatcherServlet is responsible for loading web component-specific beans like controllers, view resolvers, and handler mappings while, as I said before, ContextLoaderListener is accountable for loading middle-tier and data-tier beans which forms the back end of Spring applications.

How to fix org.springframework.beans.factory.BeanCreationException: Error creating bean with name X [Java Spring]

If you are using the Spring framework in your Java application and getting this error during startup it means Spring is not able to initialize the bean X and add it into its application context, Why? There could be multiple reasons like a typo on the spring bean name. Let's take a closer look at the stack trace to find out the real reason:

BeanInstantiationException: Could not instantiate bean class [X]: No default constructor found; nested exception is java.lang.NoSuchMethodException: X.()

Here X is the class, which is declared as Spring bean. The error clearly says that the default constructor is not present in class X.

[Solved] How to reverse a String in place in Java? Example

One of the common Java coding interview questions is to write a program to reverse a String in place in Java, without using additional memory. You cannot use any library classes or methods like StringBuilder to solve this problem. This restriction is placed because StringBuilder and StringBuffer class define a reverse() method which can easily reverse the given String. Since the main objective of this question is to test the programming skill and coding logic of the candidate, there is no point in giving him the option to use the library method which can make this question trivial.

How to check if Array contains given Number or String in Java [ Linear Search vs Binary Search]

Hello guys, one of the common coding questions from Java interviews is how to test if an Array contains a certain value or not? This is a simple question, but sometimes interview pressure makes candidates nervous. In this article, you'll learn how to solve this problem using different approaches. Since an array in Java doesn't have any inbuilt method for searching values, interviewers prefer to ask this question, to see how a candidate deals with such a situation. If you have good knowledge of Java API, then you will immediately come to know that there are alternatives available like using the binarySearch() method of Java Java .util.Arrays class or taking advantage of ArrayList contains method by first converting your array to ArrayList.

How to send HTTP Request from a Java Program - Example Tutorial

If you are thinking is it possible to send an HTTP request from a Java program and if yes, how to send a simple HTTP GET request in Java, then you have come to the right place. In this article, I'll show you how you can use the HttpURLConnection class from the java.net package to send a simple HTTP request in Java. But, first, let me answer your first question, is it possible to send an HTTP request in Java? Yes, it's possible and you can send any kind of HTTP request like GET, POST, PUT, DELETE, HEAD, or PATCH. The java.net package provides a class called HttpURLConnection, which can be used to send any kind of HTTP or HTTPS request from Java program.

How to Reverse words in String Java? [Solution]

Hello guys, if you are wondering how to reverse words in a given String in Java then you have come to the right place. Earlier, I have shared 75 Programming interview questions and In this Java Coding tutorial, you will learn how to reverse words in String. It's also one of the popular coding questions, so you will also learn how to take a requirement, how to fill gaps in the requirement by asking the right question. A String is nothing but a sentence, which may contain multiple works, or just contain a single word or it may be empty. Your program must produce a String that contains the word in reverse order, for example, if the given input is "Java is Great" then your program should return "Great is Java".

What is temporary table in Database and SQL? Example Tutorial

Hello folks, if you have heard the term temporary table online or by your colleague in a call and wondering what is temporary table, what is the difference between a normal table and a temporary table, and when and how to use it then you have come to the right place. In this blog, we shall learn how to use a temporary table in SQL. But before we go into that we need an overview of SQL. What is SQL? SQL stands for Structured query language. it is a programming language used in communicating or relating to the relational database. And this programming language performs various forms of operation in the data. It was created in the 1970s, SQL is used by database administrators, and developers writing data integration scripts, etc.

When to throw and catch Exception in Java? [Best Practice]

Exceptions are one of the confusing and misunderstood topics in Java, but at the same time, too big to ignore. In fact, good knowledge of Errors and Exception handling practices is one criterion, which differentiates a good Java developer from an average one. So what is confusing about Exception in Java? Well, many things like When to throw Exception or When to catch Exception, When to use checked exception or unchecked exception, should we catch errors like java.lang.OutOfMemoryError? Shall I use an error code instead of an Exception and a lot more? Well, I cannot answer all these questions in one post, so I will pick the first one when to catch or throw any Exception in Java.

Difference between static initializer block vs instance initializers in Java? Example

In Java, you can initialize member variables or fields in the same line you declare, in the constructor, or inside an initializer block. There are two types of initializer blocks in Java, static initializer block to initialize static variables and instance initializer block to initialize non-static fields. As the name suggests, the main difference is their purpose, instance initializer block if for instance variables, and static initializer block is for static variables. Another key difference between them is the time of execution.

How to validate phone numbers in Java? Google libphonenumber library Example Tutorial

Hello guys, if you are wondering how to validate if a given number or string is a valid phone number in a Java application then you are not alone. It's a common requirement to validate phone numbers for a Java web application, much like validating email addresses. Unfortunately, Java doesn't provide any built-in method to carry out this kind of common validation, I would love to have a validation package in Java, but don't worry there must be an open-source library to cover this deficiency, right? Yes, there is Google's phone number library which allows you to validate any phone number both international, USA specific, or any country-specific.

How to convert String to int or Integer data type in Java? Example Tutorial

Hello guys, if you are wondering how to convert a String variable to int or Integer variable in Java then you have come to the right place. Earlier, I have showed how to convert Integer to String in Java and today, you will learn about how to convert String to int or Integer variable in Java. There are 3 main ways to convert String to int in Java, first, by using the constructor of Integer class, second, by using parseInt() method of java.lang.Integer, and third, by using Integer.valueOf() method. Though all those methods return an instance of java.lang.Integer, which is a wrapper class for primitive int value, it's easy to convert Integer to int in Java.

3 ways to Convert Integer to String in Java [Example]

Hello guys, this is the second part of the String to Integer data type conversion tutorial in Java, in the first part you have learned how to convert String to Integer, and in this article, you will learn the opposite i.e. convert from Integer to String. Actually, you can apply all the tricks, which I had told you before about converting long to String, and autoboxing will take care of converting int to Integer in Java. But, if you care for performance and believe in not using auto-boxing when not needed then there are still a couple of ways that directly converts an Integer object to a String like the Integer.toString() method, which returns a String object and doesn't have any auto-boxing overhead. Let's see a couple of more ways to convert an Integer to a String in Java.

Difference between private and final class, method, and variables in Java?

Hello guys, one of the common questions among Java beginners is what is the difference between a private and final keyword in Java? The confusion arises because they are very similar and used in a similar context. For example, you can make a class, a method, and variable final as well as private. Both put some kind of restriction like you cannot override a final method in Java and the private method is not even accessible outside the class, so obviously you cannot override it.

How to Print Prime Numbers from 1 to 100 in Java [Solved]

Hello guys, today, I'll share with you a simple problem of writing a Java program to print prime numbers up to a given number like saying prime numbers from 1 to 100. It's one of the most common coding exercises for programmers learning in Java, as it gives you an opportunity to learn more about the essential operators in Java Programming. The key here is that you cannot use a library function which can simplify your job, you need to devise the algorithm for checking prime number by yourself. One of the most popular algorithms for generating prime is Sieve of Eratosthenes, which we have discussed earlier, but in this post, we will take a simpler approach.

40+ Java IO and Files Interview Questions with Answers

Good knowledge of Java IO API is important for any Java developer but many of them barely pay attention to Java IO and NIO API, and that's why they often struggle during Java interviews when a question related to Input-Output operation is asked. In the past, I have shared many Java interview questions on topics like Collections, Concurrency, JVM internals, Garbage Collection, OOP, Design Patterns, and Data structure based coding problems, which received good feedback and helped many Java developer on their Java Interview preparation. Consequently, many of my readers were also asking about Java IO and File-based interview questions and this was one of the pending items on my TODO list for quite some time.

What is InstanceOf keyword in Java [Example Tutorial]

The Java programming language and JVM are full of hidden gems and even though I am using Java for more than a decade I still get surprised by features that I didn't know for quite some time like shutdown hook, covariant method overriding, and JVM option to refresh DNS cache. The instanceof operator is also one of the rarely known features of Java, It is used to check if an object is the instance of a particular class or not. It returns true if the object is an instance of the class, otherwise, returns false. You might have seen usages of the instanceof keyword in Java while overriding the equals() method. Since for checking equality of two instances, the first step is to verify whether they are the instance of the same object or not, you can use the instanceof operator there.

Difference between trustStore vs keyStore in Java SSL

If you are confused between truststore and keystore and looking to find what exactly they mean then you have come to the right place. Earlier, I have shared free Java courses and today, I am going to tell you the difference between trustStore and keyStore in Java. Both trustStore and keyStore are important but confusing concepts and constantly tormented Java developers when they connect to servers using SSL. The main difference between trustStore vs keyStore is that trustStore (as the name suggest) is used to store certificates from trusted Certificate authorities(CA) which are used to verify certificate presented by Server in SSL Connection while keyStore is used to store the private key and own identity certificate which program should present to other parties (Server or client) to verify its identity.

Difference between 32-bit vs 64-bit JVM in Java?

Hello Java Programmers, if you want to learn Java virtual Machine in-depth and wondering what is the difference between a 32-bit and 64-bit JVM and which one should you use and why? then you have come to the right place. Earlier, I have shared the best JVM books and online JVM courses and in this article, I am going to talk about 32-bit vs 64-bit JVM and their pros and cons. This is also a common Java interview question for beginners and intermediate Java programmers. I have tried to answer this question to the point that's why this article is a short but informative one. You will find out what they are, how they are different, how much heap size, and the pros and cons of each of them.

SQL Join Tutorial - How to use JOIN Multiple Tables in SQL query? MySQL Example

Hello guys, if you are wondering how to join multiple tables in SQL to produce a combine result which contains columns from all tables but not sure how to do it then you have come to the right place. SQL Join is one of the basic concepts while working in databases or tables but yet less understood and most confusing topic for beginners and even intermediate developers. I compare Joins in SQL with Recursion in programming in terms of confusion because I have found that these two topics are special in their nature and you can't get it right with casual reading until you understand the concept and its various well. Things get worse when the table locked due to such SQL Join queries which were fired without knowing how much time it would and how big the result set could be.

Difference between Primary and Foreign keys in SQL [Answer]

The database is a collection of tables and a table is the collection of rows or records. A primary key is the data to uniquely identify a row in the table. For example, if an Employee table has millions of rows and emp_id is a primary key then it can uniquely identify that row. You can use this primary key to retrieve (SELECT) the row, update the row, and delete the row. In SQL, a table can have only one primary key but it can contain more than one column. There are two types of primary key, a simple primary key, and a composite primary key.

When to use TRUNCATE vs DELETE command in SQL?

While working with the database we often need to delete data, sometimes to create more space, sometimes just remove all data to make the table ready for the next day's transaction, or sometimes just selectively remove stale data. SQL provides a couple of handy commands to remove data e.g. truncate, delete and drop. The last one is a bit different because instead of removing data it just deletes the table. What is the difference between truncate and delete command in SQL or when to use truncate vs delete is one of the most frequently asked SQL interview questions?

How to use DROP command to remove tables in Oracle, MySQL and SQL Server

Hello guys, if you want to learn about DROP command in SQL then you have come to the right place. Earlier, I have shared the best free SQL and Database courses and several tutorials to learn SELECT, GROUP BY, and other important commands, and in this article, I will show you to use the DROP command in SQL. DROP is one of the basic SQL commands, which is used to DROP database objects. Since it's part of ANSI SQL, the DROP command is supported by all major database vendors, including Oracle, MySQL, and Microsoft SQL Server. A SQL DROP TABLE statement is used to delete a table definition and all data from a table, but DROP can also be used to drop index, view, trigger, or any other database object.

SQL Tutorial - EXISTS and NOT EXISTS Example in MSSQL

The IF EXISTS and NOT EXISTS commands in T-SQL are covered in depth in this article. When comparing data sets using subqueries, it also illustrates why EXISTS should be preferred over IN and NOT EXISTS over NOT IN. If you don't know, EXISTS is a logical operator in SQL that is used to check if rows in a database exist. If the subquery produces one or more records, it returns TRUE. The NOT EXISTS operator in SQL is the polar opposite of the EXISTS operator, and it is fulfilled if the subquery returns no results.

How to upload a file and JSON data in Postman? Example Tutorial

How to upload a file and JSON data in Postman is a common question when you are dealing with REST APIs. In order to do this, you need to send through POST request. So in this article, we are going to explain this using different examples where you can upload a single file in different ways. upload a list of files, upload as an object or upload a list of objects containing images from postman.

Top 5 Free Courses to Learn C# (C-Sharp) in 2022 - Best of Lot

Many people underestimate the power of C# and never think highly of it when they talk about programming languages. Still, the truth is that C# is one of the popular programming languages of today's world, just behind JavaScript, SQL, and Java on StackOverFlow's Developer Survey for the last couple of years. There are a lot of jobs and opportunities available for experienced C# developers. It's one of the critical languages for developers working with Microsoft technologies like Windows and SQL Server. It is also one of the most popular programming languages for developing desktop GUI, surpassing Java Swing entirely in the last couple of years. I have seen many big investment banks switched from Swing to C# for their GUI development work.

Top 5 Free Courses to Learn Deep Learning and Artificial Intelligence in 2022 - Best of Lot

Hello guys, if you are interested in learning about Artificial Intelligence and how to build AI and looking for free online resources, you have come to the right place. Earlier, I have shared free Machine Learning and Free Data Science courses, and in this article, I am going to share free Artificial Intelligence and deep learning courses for beginners. These free courses are created from Udemy, Coursera, edX, and Pluralsight and designed by experts and trusted by thousands of people who want to learn Artificial Intelligence. Clicking on this article link shows that you are very interested in learning more about artificial intelligence but wait! Learning artificial intelligence is not that easy and never will be.

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