Top 10 Java Interview Questions and Answers

Top 10 Java Interview Questions and Answers | Coding | Emeritus

Cracking an interview for a position using Java can be quite challenging—even though you’re applying for a standard software development job; the SATs appear simple given the variety of questions you might encounter. The purpose of this article is to enlighten you about the kinds of Java interview questions and answers, regardless of their nature. If you have Java on your CV, you could be questioned about everything—from the very first release to the most recent. In essence, how to stay abreast with everything? Let’s find out!

Java Interview Questions and Answers for Freshers

These questions cover critical basic Java principles that will greatly aid your preparation. Hence, the following are the top five Java interview questions and answers for new hires.

1. What are the Main Distinctions between C++ and Java?

C++ and Java are both object-oriented programming languages with some distinctions. The interviewer may inquire about the distinction between the two and add it among the top Java interview questions for freshers to assess their fundamental understanding.

C++ Java
C++ is platform-dependent. Java is platform-independent.
It creates structured programs without the need for classes or objects. With the exception of basic variables, Java is a pure object-oriented language.
Documentation comments are not supported in C++. To write documentation for Java code, Java offers documentation comments (/**…*/).
Pointers are fully supported in C++. There is no concept of pointers in Java.
C++ allows for multiple inheritances. Java does not allow for multiple inheritances.

2. What is Thread Priority?

Every thread is allocated a priority value when it is created, and higher priority threads normally take precedence in execution—although this depends on the Thread Scheduler implementation, which is OS dependant. Moreover, thread priority is an integer value ranging from 1 to 10, with 1 being the lowest priority thread and 10 being the highest priority thread.

3. Which is Preferred: The Synchronized Method or the Synchronized Block?

The synchronized block is favored because it does not lock the object, whereas synchronized methods do. In fact, if there are several synchronization blocks in the class, even if they are unrelated, it will stop the execution and place them in a wait state to obtain the lock on the object.

4. How to Get the Database Server Details in the Java Program?

We may access the database server details by using the DatabaseMetaData object. When the database connection is properly established, we can retrieve the metadata object by invoking the getMetaData() function. There are also other methods in DatabaseMetaData that may be used to determine the product name, version, and configuration parameters.

String dbProduct = metadata.getdatabaseProductName; 
DatabaseMetaData metadata = con.getMetaData();

5. What is a Java Object?

In Java, an object is a data structure that represents a physical entity. An object in Java might be a tangible entity like a vehicle or an abstract idea like a mathematical formula. In addition, each object has its own set of information and behavior. Moreover, the object’s data is the information it holds, but its behavior is its capacity to do certain activities.

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Java Interview Questions for Experienced Candidates

6. Can the Keywords “This” and “Super” be Used Together?

No, the terms “this” and “super” should not be used in the initial sentence of the class constructor. 

7. What is Java Session Management?

A session is defined as the dynamic state of random communication between the client and server. The virtual communication channel includes a string of replies and requests from both sides. The most common method of implementing session management is to create a session ID in both the client and server’s communicative discourse.

8. What is JCA in Java?

Java Cryptography Architectural (JCA) provides a framework for decryption and encryption, as well as architecture and application programming interfaces. Additionally. Java Cryptography Architecture is used by developers to integrate the application with security applications. In fact, the Java Cryptography Architecture facilitates the implementation of third-party security rules and regulations. To accomplish security, Java Cryptography Architecture uses hash tables, encryption message digests, etc.

9. What is the Distinction between System.out, System.err, and System.in?

System.out and System.err are the monitor’s default representations and may thus be used to deliver data or results to the monitor. System.out is used to output standard messages and results. Error messages are shown using System.eerr. Moreover, system.in provides an InputStream object which represents a conventional input device, such as a keyboard, by default.

10. Is it Possible to Overload the Main Method?

Yes, we may overload the main method as many times as we like. Nonetheless, the JVM prefers to use its designated calling mechanism to invoke the main function.

class Main {
    public static void main(String args[]) {
        System.out.println(“This is the Main Method”);
    }
    public static void main(int[] args){
        System.out.println(“Overloaded Integer array Main Method”);
    }
    public static void main(char[] args){
        System.out.println(“Overloaded Character array Main Method”);
    }
    public static int main(double[] args){
        System.out.println(“Overloaded Double array Main Method”);
    }
    public static void main(float args){
        System.out.println(“Overloaded float Main Method”);
    }
}

ALSO READ: What is Full Stack Development? The Ultimate 2023 Guide

Tips for Java Interview Questions and Answers

Here are a few tips for Java interview questions and answers:

  • Have a realistic resume
  • Know the fundamentals of computer science
  • Expect to be asked to write code on a whiteboard or on paper
  • Listen carefully to the questions
  • Be thorough with simple and complex Java principles and concepts

Learning more about the Java programming language is now easier than ever: In fact, Emeritus offers a multitude of online coding courses that could help you ace interviews and bag your dream job.

Write to us at content@emeritus.org

Java Interview Questions and Answers

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