How to prepare for Java Interview

Java is one of the rapidly growing programming languages worldwide. Most of the companies are chosen Java to build Desktop, Web, and Mobile applications. Product-based companies such as Google, Amazon, Facebook, or Microsoft have a different way to take Java interviews in comparison to the traditional programming interviews.

To crack the Java interview, we should have knowledge of Data structures and Algorithms like String and Java. The questions are easier and mostly based on practical work. The questions are related to the Java programming language and JDK API.

The questions are also related to the OOPs concept because Java is based on OOPs. So, we should also have great knowledge about the OOPs concepts. Java is mostly used as an application programming language, so the focus is mostly aligned with the questions related to API, Java concepts, and design patterns.

The level of Java interview depends on the experience you have. If you are a fresher applicant, the interview process and questions are not tricky, straightforward, and to the point. On the other hand, if you are an experienced guy and have experience of more than two years, the interview process and questions are tricky and not straightforward. Most questions are based on Java's advanced concept, such as swings, API, and AWT.

Which topics to prepare for Java interviews?

Java is an ocean of concepts. There are various concepts on which the interviewer can ask questions. We told you before that the level of the questions depends on the experience you have. For a fresher guy, the question can be related to the Java fundamentals like String, Collections, hashcode, API, and OOPs. The question for an experienced guy can be related to the same topics but can be too trivial for them.

1. Java Fundamentals
2. Data Structure and Algorithms
3. Object-Oriented Concepts
4. Multithreading, concurrency, and thread basics
5. Java Collections Framework
6. Date type conversion and fundamentals
7. Array
8. Garbage Collection
9. String
10. SOLID design principles
11. GOF Design Patterns
12. Abstract class and interface
13. Java basics, e.g., equal and hashcode
14. Generics and Enum
15. Java IO and NIO
16. Data structure and algorithm in Java
17. Common Networking protocols
18. JVM internals
19. Regular expressions
20. JDBC
21. Java Best Practices
22. XML Processing in Java
23. Date, Time, and Calendar
24. JUnit
25. Programming questions

All the Java developers who are serious about interviews should have knowledge of the concept as mentioned above. If we want to work in a company that develops applications based on core Java multithreading, we should know the core Java topics like multithreading and concurrency. Enum, Collections, JVM internals, GC algorithms, and Generics.

In the same way, if we want to work in a company that develops applications based on Java Web Service, we should have knowledge about REST API, SOAP API, JSON, XML, and other relevant topics.

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