Advanced Java Interview Questions and Answers For Freshers and Experience Part-21
A Scrollbar is a Component, but not a Container. A ScrollPane is a Container.
A ScrollPane handles its own events and performs its own scrolling.
170. What is the difference between a public and a non-public class?
A public class may be accessed outside of its package.
A non-public class may not be accessed outside of its package.
171. To what value is a variable of the boolean type automatically initialized?
The default value of the boolean type is false.
172. Can try statements be nested?
Try statements may be tested.
173. What is the difference between the prefix and postfix forms of the ++ operator?
The prefix form performs the increment operation and returns the value of the increment operation.
The postfix form returns the current value all of the expression and then performs the increment operation on that value.
174. What is the purpose of a statement block?
A statement block is used to organize a sequence of statements as a single statement group.
175. What is a Java package and how is it used?
A Java package is a naming context for classes and interfaces. A package is used to create a separate name space for groups of classes and interfaces.
Packages are also used to organize related classes and interfaces into a single API unit and to control accessibility to these classes and interfaces.
176. What modifiers may be used with a top-level class?
A top-level class may be public, abstract, or final.
177. What are the Object and Class classes used for?
The Object class is the highest-level class in the Java class hierarchy. The Class class is used to represent the classes and interfaces that are loaded by a Java program..
178. How does a try statement determine which catch clause should be used to handle an exception?
When an exception is thrown within the body of a try statement, the catch clauses of the try statement are examined in the order in which they appear. The first catch clause that is capable of handling the exception is executed. The remaining catch clauses are ignored.
179. Can an unreachable object become reachable again?
An unreachable object may become reachable again. This can happen when the object’s finalize() method is invoked and the object performs an operation which causes it to become accessible to reachable objects.
180. When is an object subject to garbage collection?
An object is subject to garbage collection when it becomes unreachable to the program in which it is used.