JAVA Questions and Answers Tutorial Library

18 Lessons

Is It Possible to Run a Java Program Without Main Method?

It is mostly said that running a program is not possible without the main() method. In most colleges and institutes and organizations, teachers and interviewers asked if it is possible to execute a Java program without main(). The answer should be Yes. You might have noticed that Java applets do not have main() but run on browsers.

    What Is "Write Once and Run Anywhere" Feature of Java?

    WORA, which is abbreviated as Write Once Run Anywhere, is the feature applicable to those programs which hold the capability to execute itself on any operating systems or any machine. Sun Microsystem gave this terminology for their programming language - Java.

      What Is Just-in-time (JIT) Compiler?

      In Java programming, a just-in-time (JIT) compiler is additionally given, as it has the capability to convert the bytecode of Java to the instruction, which can be feed straight to your processor. It starts running just once your program starts and compiles your source code on the fly (hence termed as just-in-time).

        What Is static Variables and Methods in Java?

        In Java language, a static keyword is implemented to make a class-level variable. Hence variables and methods having the keyword static act as part of the class and not as the class instance. static keyword can be used with a variable of any class. These types of variables do not belong to the object (or you can call it an instance of your class).

          How Many Types of Memory Areas Are Allocated by JVM?

          A Java virtual machine is an essential component that performs special types of tasks. Loading of code Verification of code Executing the code Providing a runtime environment for the users All these functions take different forms of the memory structure. […]

            What Is the Difference Between JDK, JRE and JVM?

            Java programmers must understand the differences between JDK, JVM, and JRE. So let's discuss them briefly. JDK JDK is abbreviated as Java Development Kit, which has a physical existence. It can be considered as a kit inside which resides the JRE […]

              What Is the Difference Between Classes and Objects?

              Classes and objects from the essential part of Object-oriented programming, where a class can be considered as a construct that encapsulates a group of variables and methods; whereas, an object acts as member or instance of that class.

                What is Object Cloning in Java?

                Object Cloning is one of the extraordinary features provided by Java programming which helps in creating the same copy or duplicating an object of Java class.

                  What is a Thread in Java?

                  A thread can be considered as the path taken for the execution of a program. By default, Java has one thread always running, which is the main() thread, and it is created purposefully by the JVM only.

                    What is Deadlock in Java Threads?

                    In Java, deadlock is a situation that arises in the multithreading concept. This situation may appear in cases where one of your thread is waiting for an object lock, which is acquired by another thread and the second thread waiting for object lock acquired by the first one.

                      What are The Nested Classes in Java?

                      Java allows programmers to define a class inside another class. This concept helps in grouping classes logically. Nested classes are those classes that are defined or created within another class.

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