latest interview questions on core java in java

The null is not a keyword. No, “null” is not a keyword in Java. In Java, “null” is a literal that represents the absence of a value or a null reference. Keywords in Java are reserved words that have a specific meaning and cannot be used as identifiers. Examples of keywords in Java include “class,” “public,” “static,” … Read more

The stop(), suspend() and resume() methods have been deprecated in JDK 1.2. In Java, the stop(), suspend(), and resume() methods were deprecated starting from JDK 1.2 and have been strongly discouraged for use. These methods were deemed problematic due to their potential to cause deadlock and other thread-related issues. The recommended approach for controlling the execution of threads is to … Read more

Yes, a lock can be acquired on a class. This lock is acquired on the class’s Class object. Yes, in Java, it is possible to acquire a lock on a class. In Java, every class and object has an associated lock, also known as a monitor. This lock is used to control access to the critical section … Read more

With respect to multithreading, synchronization is the capability to control the access of multiple threads to shared resources. Without synchronization, it is possible for one thread to modify a shared object while another thread is in the process of using or updating that object’s value. This often leads to significant errors. In the context of … Read more

Objects that subclass the Observable class maintain a list of observers. When an Observable object is updated it invokes the update() method of each of its observers to notify the observers that it has changed state. The Observer interface is implemented by objects that observe Observable objects. In Java, the Observer and Observable classes were part of the java.util package to implement the … Read more