core java interview questions for 10 years experience

Core Java Interview Questions for 10 Years Experience

When it comes to Java interviews, it's essential to be prepared for a wide range of questions that can test your skills and knowledge. In this article, we'll explore some of the most commonly asked Java interview questions for experienced professionals.

One of the fundamental concepts in Java is string immutability. This means that once a string is created, its value cannot be changed. But why is this the case? The answer lies in the way strings are implemented in Java. Strings are stored as a sequence of characters, and each character has a specific memory address. When you try to modify a string, you're actually creating a new string object with the modified characters.

Transients variables are another important concept in Java. These are variables that are not serialized when an object is written out to a stream or file. This can be useful in situations where you don't want certain data to be persisted. For example, you might have a class that contains sensitive information, such as passwords or credit card numbers. By making these fields transient, you can ensure that they are not written to disk when the object is serialized.

Abstract classes are another important concept in Java. While abstract classes cannot be instantiated, they can contain both abstract and non-abstract methods. Abstract methods must be implemented by any subclass that inherits from the abstract class. Non-abstract methods, on the other hand, can be overridden or invoked directly.

HashMaps and HashSets are two popular data structures in Java. While they share some similarities, there are key differences between them. HashMaps use a hash table to store its elements, which allows for fast lookups and insertions. HashSets, on the other hand, do not allow duplicate values and use a hash table to store its elements.

When working with custom objects in a HashMap, you must override the equals() and hashCode() methods. This is because these methods are used by the HashMap to determine whether two objects are equal or have the same hash code.

The Object class is the base class for all Java classes. It provides several important methods, including finalize(), clone(), toString(), notifyAll(), notify(), wait(), equals(), and hashCode(). These methods can be overridden in custom classes to provide specific behavior.

In conclusion, these questions cover some of the most commonly asked Java interview questions for experienced professionals. By understanding these concepts and being prepared to answer questions about them, you'll be well on your way to acing your next Java interview.

Additional Resources

For a more in-depth explanation of each question, please refer to the links provided throughout this article.

Core java interview questions for 10 years experience