Tuesday, July 23, 2019

How to reverse a linked list in Java using Recursion and Iteration (Loop) - Example

This is one of the class coding problems from Programming job interviews. It may seem easy to reverse a linked list but when you go around doing the actual task, it's not that easy, especially for first-timers. There are a couple of algorithms exists to reverse a singly linked list in Java like you can use the three-pointers approach or solve this problem using a Stack, or simply using Recursion without the external stack. As I had pointed out on the earlier post about linked list, that reversing a linked list is one of the most popular linked list based data structure interview question. This means, you just can't afford to prepare this one, before going for any programming interview. Despite being so common, It's not easy to solve this problem on the fly.

Top 5 Tableau Online Courses and Certifications for Data Scientist and Data Engineers - Best of Lot

In the era of Big Data and Data Science, Data Visualization and Analytics have become really important. Data visualizations like dashboards and charts help you to better understand the data and provides you insights. They also help simplify complex data sets into concise images and charts that clients and users can more easily digest. What would you do with the data if you cannot analyze it to gain the insights which can help with your business growth and some path-breaking discoveries and that's where Data Visualization and Analytics tools like Tableau helps a lot.

3 Ways to convert String to Boolean in Java? Examples

You can convert a String object to 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 e.g. String to Integer and String to Long. You can use valueOf() method to convert String to Boolean object and parseBoolean() method to convert 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" string. 

Monday, July 22, 2019

Top 5 Course to learn Apache Maven for Java Developers

The Apache Maven or commonly known as just "Maven" is an important tool for Java Programmers. It allows you to build your project, manage dependencies, generate documentation and lot more. I can vouch for Maven's usefulness because I have come from the pre-Maven world of Software development, where you need to manage all the JAR files required by your project. It may seem easy to you that just download the JAR file but it's not so easy in practice.  For example, you added a new library in your project say Spring framework which also needs log4j but you thought log4j is already there so you didn't do anything, only to realize that your application is not starting anymore and throwing long and convoluted errors. This can happen because of version mismatch like Spring needed a higher version of log4j than available in your project.

Top 6 Free Online Database and SQL Courses for Programmers

Hello guys, we are already in the first week of New year and everyone is talking about their goals to improve them as a better person, a better programmer, or get better health. If you have also made your goal and one of them is to improve your SQL skill then you have come to the right place because I am going to share some of the free courses to learn and master SQL this year. As you already know, SQL is one of the essential skill and much more important than any fancy library or framework you are thinking to learn.  If you ask me which two skill every programmer should have, I would say SQL and UNIX, these two have survived for a long time and will survive for many coming decades. SQL is also very interesting, once you get a hang of it, you would love to write queries and analyzing the performance of your queries.

Sunday, July 21, 2019

How to fix invalid target release: 1.7, 1.8, 1.9, or 1.10 Error in Maven Build

If you are building your Java project using Maven, maybe in Eclipse or from the command prompt by running mvn install and your build is failing with an error like "invalid target release: 1.7" or "invalid target release: 1.8" then you have come to the right place. In this article, I'll show you the reason why this error occurs and how you can deal with these errors even with higher Java version like Java 9, 10 installed on your machine, or maybe with Java 11 in the coming month. The root cause of the problem is that you have specified a higher Java version in your pom.xml file for Maven compiler plugin then what Maven knows in your system, and that's why it's saying invalid target release.