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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.

Top 5 books to Learn AWS


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).

best books to learn AWS

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).

best books to learn AWS


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. 

Top 20 Java Access Modifier Interview Questions Answers

Access modifiers is one of the essential concept in Java and every programmer should be familiar with, and because of its importance, its also a popular topic in Java interviews. Access modifier can be applied to class, method, fields, and variables and as the name suggests they control the access. Like who can access that particular class, method or variable. For example, public modifier provides universal access which means any public class, method or variable is accessible by everyone and everywhere. In other words, you can access a public class both within the package and outside the package. 

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 40 Perl Interview Questions for Beginners [1 - 2 Years Experienced]

Hello guys, if you have been working as a professional Software developer then you may have heard about Perl, one of the most powerful scripting languages. Perl is really great when it comes to creating reports, write scripts to analyze text, and connect to DB, load data and generate reports. Perl is even more important for support professionals, business analysts, and IT professionals who need to work in the field of operations. That's why Perl questions are quite common during Software developer and IT support interview, especially if the Job description mention Perl or you have added Perl as a skill in your resume or LinkedIn Profile.

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.