java 13 interview questions and answers

class variable is a static variable and does not belong to instance of class but rather shared across all the instances – member variable belongs to a particular instance of class and can be called from any method of the class – automatic or local variable is created on entry to a method and has … Read more

Ans: So that it can be invoked without creating an instance of that class. In Java, the main method is required for the execution of a Java program. The main method serves as the entry point for the Java Virtual Machine (JVM) to start the execution of the program. To understand why the main method … Read more

Without layout managers, Java programmers are faced with determining how their GUI will be displayed across multiple windowing systems and finding a common sizing and positioning that will work within the constraints imposed by each windowing system. When Java programmers don’t use layout managers, they often encounter several problems related to the positioning and sizing … Read more

A thread class may be declared as a subclass of Thread, or it may implement the Runnable interface. In Java, there are two basic ways to define classes that can be run as threads: Extending the Thread class: You can create a new class that extends the Thread class and override its run() method. The run() method contains … Read more

Synchronized methods are methods that are used to control access to an object. A thread only executes a synchronized method after it has acquired the lock for the method’s object or class. Synchronized statements are similar to synchronized methods. A synchronized statement can only be executed after a thread has acquired the lock for the … Read more