OOPS Interview Question in Java:- OOP's is the most important topic of the interview, especially for JAVA. I am providing some most important interview questions based on OOP'S. 1)   What is OOPS? 2)   Why we use OOP'S technique in programming? 3)  What is the full form of OOP'S? 4)  What is the definition of Object, Class depends on object or Object is depend on class? 5) What is the difference between Object and Instance(reference)? 6)  What is the Garbage collector in Java, how it works? 7)  What are the Access modifier(Access Control, Access Specifier) and non-access modifiers in Java? 8) What is an immutable object in Java? 9) What is Singleton class, Concreate class,  Inner class in Java? 10) What is the final class, the final method, and the final variable in Java? 11)  What is another way to protect class from an inheritance except for the final class? 12) What is init block, static block, and constructor, if all three pres...

---Question for all Java learners and Java Job seeker--- In this article, I will discuss, some important questions of java. What is System.out.println() in Java?  What is public static void main(String args[])? If you know advance questions then ok, if you do not know silly questions then you will definitely be rejected on the interview hence focus on fundamentals then go for an advance topic. What is System.out.println() in Java?   System is the predefined final class of Java, which exists under java.lang package, It is used to manage input and output operation in java. When we want to take input from the keyboard in Java then System.in the reference variable will use, if we want to display output on any output screen such as to monitor, laptop, desktop, etc then System.out the reference variable will work. out is the static reference or static variable of PrintStream Class which is declared under System class. println():-   It is the predefined method of Pri...

  Java Unique Interview Question:- Q) WAP to print data without using System.out.printlln()?  import java.io.*; class Addition {    public static void main(String args[]) throws IOException    {      FileOutputStream fo= new FileOutputStream(FileDescriptor.out)      OutputStreamWriter o= new OutputStreamWriter(fo, "ASCII")      BufferedWriter out = new BufferedWriter(o, 512);      out.write("test string");      out.write('\n');      out.flush();    }  } Q)  WAP to calculate addition without using + operator? class Addition {    public static void main(String args[]) throws IOException    {      int a=100,b=20;      while(b>0)      {          a++;          b--;      }      Syste...

Core Java Interview Question for an experienced candidate Top 20 Java Interview Question, Check Your Java Skills. 1)  What is annotation in Java, How we can create custom annotation? 2)  What is Reflection API in Java? 3)  How we can create Checked User Define Exception and  Unchecked User Define Exception? 4)  What is Inner class, Local Inner Class, Static Inner Class, Anonymous Class 5)   What is a Generic Class in Java  How we can define Custom Generic Class 6)  How we can Synchronize Array List? 7)   Which is the best Collection class to add and edit elements concurrently? 8)   What is the Marker interface, the difference between annotation and marker Interface? 9)    What will be the output when we call run() manually in Thread? 10)   What is the Design pattern in Java define Creational, Behavioral, and Structural Design Pattern? 11)    Difference between Comparable and Comparator? 12)...