5 Difference between BufferedReader and Scanner class in Java? Example

Hello guys, welcome to my blog. Today, we'll discuss another interesting Java interview question, BufferedReader vs Scanner. It's not only important from an interview point of view but also to work efficiently with Java. Even though both BufferedReader and Scanner can read a file or user input from the command prompt in Java, there are some significant differences between them. One of the main differences between BufferedReader and Scanner class is that the former class is meant to just read String or text data while the Scanner class is meant to both read and parse text data into Java primitive types like int, short, float, double, and long.

How to join two threads in Java? Thread.join() example

You can join two threads in Java by using the join() method from java.lang.Thread class. Why do you join threads? because you want one thread to wait for another before starts processing. It's like a relay race where the second runner waits until the first runner comes and hands over the flag to him. Remember, unlike sleep(), join() is not a static method so you need an object of java.lang.Thread class to call this method. Now, who calls and who wants, and which thread dies? for example, if you have two threads in your program main thread and the T1 which you have created. 

How to stop a thread in Java? Example

Today we're going to learn about how to stop a thread in Java. It's easy to start a thread in Java because you have a start() method but it's difficult to stop the thread because there is no working stop() method. Well, there was a stop() method in Thread class, when Java was first released but that was deprecated later. In today's Java version, You can stop a thread by using a boolean volatile variable.  If you remember, threads in Java start execution from the run() method and stop, when it comes out of the run() method, either normally or due to any exception. You can leverage this property to stop the thread. 

Can You Create Instance of Abstract class in Java? Answer

Hello Java Programmers, how are you doing? Hope you are doing well. It's been a long since  I shared a core Java interview question in this blog, so let's start with that. Earlier I have shared one of the frequently asked questions in Java, can we make an abstract class final in Java and my readers really liked it and asked for more such questions. So, today I am going to talk about whether you can create an instance of an Abstract class in Java or not? This is another interesting core Java question that you will find on telephonic interviews, a written test that has multiple-choice questions and most notably Oracle certified Java programmer certification like OCAJP 8  and OCAJP 11.

ArrayList vs Vector in Java? Interview Question Answer

ArrayList vs Vector in Java
ArrayList and Vector are the two most widely used Collection classes in Java and are used to store objects in an ordered fashion. Every Java programmer which is introduced to Java Collection Framework either started with Vector or ArrayList. For beginners Difference between Vector and ArrayList in Java and LinkedList vs ArrayList are the two most popular Java Interview questions. ArrayList vs Vector is not only important from an interview perspective but also on the effective use of Java Collection API. 

Difference between static and non static nested class in Java? Example

Static vs. non Static class in Java

In Java, you can make a class either static or non-static. Now, what is the difference between making a class static vs. non-static? Well, there is a lot of difference between them. First of all, there are two kinds of classes in Java, one is called a top-level class, and the other is called a nested class. As the name suggested, a top-level class is a class that is declared in the .java file and not enclosed under any other class. On the other hand, a nested class is declared inside another class. The class which enclosed nested class is known as Outer class. 

Difference between throw vs throws in Java? Answer

throw vs throws in Java

throw and throws are two Java keywords related to the Exception feature of the Java programming language. If you are writing a Java program and familiar with What is Exception in Java, it's a good chance that you are aware of What is throw and throws in Java. In this Java tutorial, we will compare throw vs throws and see some worth noting differences between throw and throws in Java. Exception handling is an important part of the Java programming language which enables you to write robust programs. There are five keywords related to Exception handling in Java like try, catch, finally, throw, and throws.

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. 

[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.

[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 24 Java Date, Time, and Calendar Interview Questions Answers

The Date and Time API is a significant one for day-to-day Java development work, but many interviewers don't ask enough questions on this topic. Most of the questions are based on either Java Collection framework like  HashMap, ConcurrentHashMap, or ArrayList or multi-threading concepts like volatile, synchronized, and atomic variables. This is not good, and many interviewers have realized that a good understanding of date and time API is also important for a good Java developer. That's the main reason for increasing date, time, and calendar-based Java interview questions in recent times, particularly in the last couple of years.

Top 50 Core Java Interview Questions and Answers for Beginners

Hello guys, If you are preparing for your next Core Java interview and looking for some common questions to practice or check your knowledge, then you have come to the right place. In this article, I'll share 50 Core Java Interview Questions from various companies. I have already discussed the answers to these questions in this blog or Javarevisited, so I have just put the link and given hint or mentioned the key point you need to know to answer these questions. First, you should try to answer it yourself, and if you cannot then go to the link and find the answer. You can also compare your answer with mine and learn a few things here and there.

Difference between StringBuilder and StringBuffer in Java with Example

If you are in a hurry and heading straight to interview then I won't take much of your time, In a couple of words, the main difference between StringBuffer and StringBuilder is between four parameters, synchronization, speed, thread-safety, and availability. StringBuffer is synchronized and that's why thread-safe, but StringBuilder is not synchronized, not thread-safe and that's why fast. Regarding availability, StringBuffer is available from Java 1.0 while StringBuilder was added in Java 5. 

Top 70 Java Interview Questions for Junior Developers [1 to 2 Years Experienced]

Java Developer Interviews are very different than traditional software developer interviews. You can clear a Java interview without even writing a single line of code, Yes, this is true, you can become a Java developer without someone asking you to write a function in a Java interview. Though it's not the case everywhere and many companies are increasingly including a coding test in their Java developer interview process, but there are many companies and start-ups where you can get a Java job without writing a single line of code. All you need to do is learn those popular Java questions, which have been asked for ages, and mostly test whether a candidate is familiar with essential Java concepts or not like abstract class and interface. 

15 Technical Core Java Interview Questions Answers for Experienced Developers

When the experience of a Java Programmer grows in the years e.g. when it goes from beginner years ( 2 to 4) to more experience or sort of senior level ( 5 to 7 years), Core Java Interview Questions also change a bit. Of course, basics like data structure, algorithms, and object-oriented programming remains the same, but types of questions will become more advanced and their answers will definitely need to be more detailed and accurate. I often receive queries about core Java questions asked to a senior developer with 5 to 6-year experience, or, sometimes, I am going for an interview of a senior Java developer, what kind of questions I should expect. 

How to check if strings are rotations of each other in Java? String Rotation Example Solution

String-based algorithmic questions are very popular in Java interviews e.g. checking if two String is the anagram of each other (see), or checking if given String is a palindrome (see), or just finding permutations of given String (see). One of such popular String-based interview questions is about to check if two Strings are a rotation of each other in Java. In order to solve this question, you should know what is String rotation? Well, A string is made of characters and you just rotate the String around any character like "programming" will become "ingprogramm" if we rotate the String on the trailing character 3 times.

Difference between Static and Dynamic binding in Java

Hello guys, if you are wondering what is difference between static and dynamic binding and how it affect your program execution in Java then you are at right place. When you call a method in Java, it is resolved either at compile time or at runtime, depending upon whether it's a virtual method or a static method. When a method call is resolved at compile time, it is known as static binding, while if method invocation is resolved at runtime, it is known as Dynamic binding or Late binding. Since Java is an object-oriented programming language and by virtue of that it supports Polymorphism. Because of polymorphism, a reference variable of type Parent can hold an object of type Child, which extends Parent.

What is transient variable in Java? Serialization Example

What is a transient variable in Java?

transient variable in Java is a variable whose value is not serialized during Serialization and which is initialized by its default value during deserialization, for example for object transient variable it would be null. This behavior can be customized by using a custom Serialized form or by using the Externalizable interface. A transient variable is used to prevent any object from being serialized and you can make any variable transient by using the transient keyword. You cannot make a local variable transient through and it's only the member variables which can be transient. 

Difference between HashSet and HashMap in Java? Answered

HashSet and HashMap in Java
Hello friends, if you have given Java developer interview then there is good chance that you may have come across questions like Difference between HashSet vs HashMap or HashSet vs TreeSet etc. In this article, we are going to discuss differnece between HashMap and HashSet, two of the popular Collection classes from JDK. The HashSet vs HashMap is a classical Java Collection interview question that focuses on What are differences between HashSet and HashMap in terms of features, usage, and performance. If you are in Java programming even for a year or so, you are likely to be familiar with What is HashSet in Java and What is HashMap in Java, these two are the most popular collection classes. 

What is PATH and CLASSPATH in Java? Path vs ClassPath Example

What is PATH and CLASSPATH in Java
The PATH and CLASSPATH are the two most important environment variables of the Java environment which are used to find the JDK binaries used to compile and run Java in windows and Linux and class files which are compiled Java bytecodes. From my personal experience I can say that PATH and CLASSPATH are the two most problematic things for beginners in Java programming language due to two reasons; first because in most Java courses nobody tells details of what is a PATH and CLASSPATH, What do PATH and CLASSPATH do, What is meaning of setting PATH and CLASSPATH, What happens if we do not set them, Difference between PATH vs CLASSPATH in Java or simply How Classpath works in Java, etc.