Many enterprise companies use Java to write large-scale applications. Being a Java developer means you can switch between companies easily to increase your pay. However, to do so, you need to crack the java coding interviews presented to you by these companies.
Coding interviews are relatively standardized in the tech world. However, suppose you’re wondering how to crack the java coding interview. In that case, you first must understand coding interviews and anything specific that may come up during Java coding interviews.
Below are some tips from AlgoMonster and advice on doing well in Java coding interviews.
Java Coding Interview Preparation
The first thing to understand is that Java coding interviews are not about the day-to-day Java coding skills you may already have. Coding interviews is a specific skill explicitly required for interviews. Companies want to find and hire people as quickly as possible, which means they need to assess your skills efficiently.
Java Coding Interview Preparation Time
In general, you want a minimum of four weeks to prepare for a Java coding interview. This preparation gives you the time to practice java coding interviews and prepare for the types of questions the interviewer will ask you. This preparation time also lets you see where your weaknesses are to study and improve in those areas.
Suppose this is your first java coding interview, then you might even need a full 12 weeks to prepare, which may sound like a lot of time. But it all depends on where your skills are right now and how long you have until an actual interview.
Java Coding Interview Standard Topics
All coding interviews have some standard topics covered, which are Data Structures and Algorithms. Therefore, you should have a general understanding of both of these topics, know the most common for each area, and when best to use them.
The common data structures you need to understand are:
- Linked Lists
- Hash Tables
- Hash Maps
The common algorithms you need to understand are:
- Sorted and Searching
- Greedy Algorithms
- Divide and Conquer
Java Coding Interview Practice
You must practice your java coding interviews. Almost all coding interviews will be 30-60 minutes, which means you need to understand, implement, test, and optimize your code in an extremely short amount of time.
You need to go online to review practice coding interviews on sites like LeetCode.com and practice every day with at least one question.
Review Your Practice Coding Interviews
After each coding interview practice you do, you need to review the entire process. For example, did you solve the problem in a reasonable amount of time? Did you use the best approach to solve the problem? Could your method or code be improved in any way?
It’s essential to look at how you did and objectively grade yourself to see where you need to improve.
Review Practice Coding Interviews With Something
A vital part of coding interviews is talking through your code with the interviewer, including the problem and solution. Therefore, you need the ability to code and talk simultaneously. You need to be an effective communicator and not just provide random facts about the code.
Get a colleague or a friend who is a coder and run through a coding interview with them. After the coding interview, discuss with them how you did. Were your explanations clear and concise? Do they did you did a good job, or is there room for improvement?
Communicating your approach is as important as the actual code you are writing. So make sure you practice this as well.
Coding Interview Preparation
Java coding interviews and the questions and topics asked of you will depend on your role and your experience. If you are a junior developer, the questions are going to be on the easier side. As a junior developer, the interviewer won’t expect you to know about system design or how to tackle multithreading or advanced topics.
However, suppose you’re a senior developer. In that case, the questions will be a lot more complex, involve system design, and may even have some tricks to see how well you know Java and its intricacies.
Java Coding Interview Types of Questions
When it comes to coding interviews about Java, there are specific topics you will need to review and address any areas that you lack knowledge of.
Java is fortunately for day-to-day activities full of options and many different methods of doing things. But, unfortunately, for coding interviews, this means you have a vast range of different topics that an interviewer could give to you in the coding interview questions.
While Java can be an OOP, coding interview questions will generally stick with APIs, Java Concepts, and Design Patterns. As well as things like Swings and AWT.
Below is a general list of topics you will need to review to crack the java coding interview:
- Abstract class and interface
- Common Networking protocols
- Data Structure and Algorithms
- Date type conversion
- Date, Time, and Calendar
- Garbage Collection
- Generics and Enum
- GOF Design Patterns
- Java basics like equal and hashcode
- Best Practices of Java
- Java Collections Framework
- Java IO and NIO
- JVM internals
- Multithreading, concurrency, and threads
- Object-Oriented Concepts
- Regular expressions
- SOLID design principles
- XML Processing in Java
Final Thoughts on Cracking the Java Coding Interview
Cracking the java coding interview is going to require a general understanding of coding interviews. This required understanding includes things like discussing your code, the time limits imposed, and the type of questions that an interviewer will ask of you.
From a Java perspective, there are undoubtedly specific topics you need to ensure you’re fully informed about, which are listed above. You also need to understand Java and best practices that you may not follow due to not starting your programming life in Java.
The number one piece of advice that any Java developer needs when trying to crack the coding interview is to practice. You must practice java coding questions online as much as possible before your actual coding interview. Without practice, it will be challenging to do well in the coding interview, which will affect your options for employment.