70+ Coding Interview Questions for Software Engineers and Developers in 2025

There are a lot of computer science graduates and programmers applying for programming, coding, and software development roles at startups like Uber and Netflix and big organizations like Amazon, Microsoft, and Google.  They are also quite popular on service-based companies like Infosys, TCS, or Luxsoft, but many of them have no idea of what kind of programming interview questions to expect when you’re applying for a job with these companies. Things have also changed a lot in the last few years and coding interviews have become tougher. Now you need to go through a couple of coding interview rounds but you also need to prepare for System design problems which wasn’t normal in the last decade.

Access Modifiers in Java - Public, Private, Protected, and Package Examples

public, private, protected and package or default are four access modifiers available in Java. These access modifiers provide Java programmers to control the accessibility or visibility of a class, method, or any field of a class. A good understanding of public, private, or protected modifiers is required in order to implement proper encapsulation in Java and create a Java program that is easier to maintain. In this Java tutorial, we will see what is public, private, protected and default modifiers are, which modifiers can be used with top-level class and nested class, and what is the difference between public, private, protected, and default modifiers in Java.

How to display date in multiple timezone in Java with Example - PST GMT

We can use SimpleDateFormat class to display a date in multiple Timezone in Java. While working in a global Java application it's quite common to display dates in the different time zone, classical example is Server is running on either PST or GMT timezone and clients are global or at least running on global trading hubs like Hong-kong, Mumbai, Tokyo, London, etc. Unfortunately, the Date and Time API in Java is quite tricky and until you have a good understanding of Date and Time classes and methods like Calendar, SimpleDateFormat, and thread-safety issues, You can easily create bugs. 

JDBC - How to Convert java.sql.Date to java.util.Date in Java with Example

How to convert java.sql.Date into a java.util.Date and vice-versa is a popular JDBC interview question which is also asked a follow-up question of the difference between java.sql.Date and java.util.The date which we have seen in our last article. Since both SQL date and Util date store values as a long millisecond, converting them back and forth is easy. Both java.sql.Date and java.util.The date provides a convenient method called getTime() which returns a long millisecond equivalent of a wrapped date value. Here is a quick example of converting java.util.Date to java.sql.Date and then back to util Date. 

How to read file in Java using Scanner Example - text files

Reading a file with Scanner
From Java 5 onwards java.util.Scanner class can be used to read file in Java. Earlier we have seen examples of reading file in Java using FileInputStream and reading file line by line using BufferedInputStream and in this Java tutorial, we will See How can we use Scanner to read files in Java. Scanner is a utility class in java.util package and provides several convenient methods to read int, long, String, double etc from a source which can be an InputStream, a file, or a String itself.

How to read User Input from Console in Java? Scanner Example

Apart from reading files, Scanner can also read user input from Console in Java. Just like in the case of reading files, we have provided File as a source for scanning, We need to provide System.in as a source to scan for user input in Console. Once you created and initialized java.util.Scanner, you can use its various read method to read input from users. If you want to read String, you can use nextLine(), if you want to read integer numbers, you can use nextInt(). 

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.

How to compare two Arrays in Java to check if they are equal - [String & Integer Array Example]

Hello guys, one of the common Programming, the day-to-date task is to compare two arrays in Java and see if they are equal to each other or not. Of course, you can't compare a String array to an int array, which means two arrays are said to be equal if they are of the same type, has the same length, contains the same elements, and in the same order. Now, you can write your own method for checking array equality or take advantage of Java's rich Collection API. Similar to what you have seen while printing array values in Java, java.util.Arrays class provides convenient methods for comparing array values.

Top 10 Free Udemy Courses to Learn Coding and Web Development in 2025 - Best of Lot

When I was a little kid, I remember reading somewhere that coding will be the language of the future. I was intrigued. What was this new language that I didn't know about and nobody around me spoke? How was it going to be the language of the future? Before we get to the 10 free Udemy courses that will teach you coding, let me tell you a little more about what coding is.  

Top 6 Books to Improve Coding and Programming Skills in 2025 - Must Read, Best of Lot

Learning a Programming language, like Java, Python, or C++ is easy, but learning to write good code is not. Writing good code is more Art than Science and also an important differentiating factor between an average programmer vs. a good programmer. Since most of the programmers often look for inspiration and resources to improve their coding skill, I decided to share some of the good books which can help them to improve their coding.  Since many universities, colleges, and training courses only teach programming languages but not the art of coding, it still remains one of the self-learned skills which many programmers acquired either in Job or working on real-world projects.

Top 21 Websites to Learn Programming for FREE in 2025 - Best of Lot

Hello folks, if you want to learn Coding from scratch and looking for some free online training websites or are someone who is learning programming and Coding by yourself and looking for some fantastic free websites and coding platforms, then you have come to the right place. Earlier, I shared free courses to learn Java, Python, and JavaScript, and In this article, I will share 21 websites to learn Coding for FREE. These are absolutely free online training websites and platforms you can use to learn programming languages and essential software skills like web development,  machine learning, automation, and app development for free from the comfort of your office and home.

Is Cracking the Coding Interview book Still worth it in 2025? Review

Hello guys, if you are preparing for Programming Job interviews and wondering whether the classic Cracking the Coding Interview book by Gayle Laakmann McDowell is still worth it in 2025 then you have come to the right place.  In the past, I have shared best books and courses for coding interviews where I mentioned this book and today, I am going to review this book in depth. This was one of the first book I used to prepare for coding interview and due to its focus on evergreen topic, I am happy to say that it's still relevant, but whether it's good enough now is another question, which we will find in this article.

How to Count number of 1s (Set Bits) in a binary number in Java [Solved]

Good morning folks, In today's article, we are going to discuss one of the frequently asked bit manipulation-based interview questions, how do you count the number of set bits in a given bit sequence?  Bit Manipulation is an important topic in programming interviews and a good programmer should have sufficient knowledge and skill to work with binary numbers. This kind of question tests the skill of the programmer. Sometimes, it is also asked as to how to count the number of 1s (ones) in a given number? Both are the same question because 1 is also known as set bit.  For example, if the given input is 1000110010 then your program should return 4, as three are only four set bits in this bit sequence.

How to count a number of words in given String in Java? [Solved]

Can you write a method in Java that accepts a String argument and returns a number of words in it? A word is a sequence of one or more non-space characters i.e. any character other than '' (empty String). This should be your method signature:

public int count(String word);

This method should return 1 if the input is "Java" and return 3 if the input is "Java, C++, Python". Similarly a call to wordCount("    ") should return 0. 

Where to Start Learning to Code in 2025? Resources

Hello guys, if you want to coding and looking for best online courses to learn to code then you have come to the right place. In this article, I am going to share best coding and programming online courses. Coding, computers, programming, and IT has been a buzzword all through the world for last 10-15 years. In the same durations, we have seen several tech companies touch a milestone of a couple of trillion dollars in market cap. Everyday, in different parts of the world, we see new companies and organizations growing at unprecedented pace. 

Top 95 Programming Interview Questions Answers to Crack Any Coding Job Interview

Hello guys, if you are preparing for your next Programming Job interview and looking for frequently asked Coding or Programming questions to practice then you have come to the right place. In this article, I am going to share some of the most commonly asked Coding questions from Programming Job interviews. In order to do well on the Coding interview you need practice, you just can't go there and try to solve the coding problems in a limited time, that's actually one of the most common reasons to fail your programming Job interviews.  Sometimes, the interviewer also asks a little bit easier coding questions on a telephonic interview like revering array in place or reversing a string in place.

Top 21 String Programming and Coding Interview Questions With Solutions

In this article, I am going to share 21 of the most common String-based Programming and Coding interview questions from Java developer interviews. These questions require you to write code to solve the problem and they are different from traditional Java String questions like how the substring method works in Java? or when to use the intern() method of String in Java? Since coding and problem solving are an important part of any programming job interview, it's imperative that you know how to solve them in time and in a pressure situation, which comes only after doing practice with the right set of questions. Since these questions are already tried and tested and appeared in many interviews, they will provide you the experience you need to crack your coding interview.

What is static in Java? Example Tutorial

What is static in Java
Static in Java is related to class if a field is static means it belongs to the class, similarly static method belongs to classes and you can access both static method and field using the class name, for example,  if count field is static in Counter class than you can access it as Counter.count, of course, subject to restriction applied by access modifier like private fields are only accessible in class on which they are declared, protected fields are accessible to all classes in the same package but only accessible in subclass outside the package, you can further see private vs protected vs public for complete details on access modifier. 

10 Common Coding Mistakes Every Java Developers Should be aware of

Hello guys, Java is a versatile and powerful programming language, but it's not immune to common coding mistakes that developers may inadvertently make. These errors can lead to unexpected behavior, performance issues, and even security vulnerabilities. In this article, I am going to share 10 such common coding mistakes Java developers often encounter, provide examples of each mistake, explain why they are problematic, and offer solutions to correct them. I strongly recommend every Java developer whether he is beginner, intermediate or senior developer to go through the list once so that you are aware of these mistakes. If you have been coding in Java then most likely you would have also made the same mistake, if you do, let us know in comments so that we all can learn from each other. 

How to Remove all white spaces from String in Java? From Start, End and between Words Examples

String API in Java provides several utility methods to remove white space from String in Java, from the beginning, end, and between words. White space means blank space including tab characters. One of the classic methods to remove white space from the beginning and end of a string in Java is the trim() method, which removes white space from beginning and end. While using the trim() method, the key thing to remember is that trim() returns a different String object than the older one because String is immutable in Java