A public class may be accessed outside of its package. A non-public class may not be accessed outside of its package.

The default value of the boolean type is false.

Try statements may be tested.

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.

A statement block is used to organize a sequence of statements as a single statement group.

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.

An Abstract class declares have at least one instance method that is declared abstract which will be implemented by the subclasses. An abstract class can have instance methods that implement a default behavior. An Interface can only declare constants and instance methods, but cannot implement default behavior.

The purpose of garbage collection is to identify and discard objects that are no longer needed by a program so that their resources can be reclaimed and reused. A Java object is subject to garbage collection when it becomes unreachable to the program in which it is used.

With respect to multithreading, synchronization is the capability to control the access of multiple threads to shared resources. Without synchonization, it is possible for one thread to modify a shared variable while another thread is in the process of using or updating same shared variable. This usually leads to significant errors.

Map is Interface and Hashmap is class that implements that.

The HashMap class is roughly equivalent to Hashtable, except that it is unsynchronized and permits nulls. HashMap allows null values as key and value whereas Hashtable doesnt allow. HashMap does not guarantee that the order of the map will remain constant over time. HashMap is non synchronized and Hashtable is synchronized.

AWT are heavy-weight componenets. Swings are light-weight components. Hence swing works faster than AWT.

public : Public class is visible in other packages, field is visible everywhere class must be public tooprivate : Private variables or methods may be used only by an instance of the same class that declares the variable or method, A private feature may only be accessed by the class that owns the feature.protected : Is available to all classes in the same package and also available to all subclasses of the class that owns the protected feature.This access is provided even to subclasses that reside in a different package from the class that owns the protected feature.default :What you get by default ie, without any access modifier ie, public private or protected.It means that it is visible to all within a particular package.

A checked exception is some subclass of Exception or Exception itself, excluding class RuntimeException and its subclasses.Making an exception checked forces client programmers to deal with the possibility that the exception will be thrown. eg, IOException thrown by java.io.FileInputStream's read method·Unchecked exceptions are RuntimeException and any of its subclasses. Class Error and its subclasses also are unchecked. With an unchecked exception, however, the compiler doesn't force client programmers either to catch theexception or declare it in a throws clause. In fact, client programmers may not even know that the exception could be thrown. eg, StringIndexOutOfBoundsException thrown by String's charAt method· Checked exceptions must be caught at compile time. Runtime exceptions do not need to be. Errors often cannot be.

No in this case the finally block will not execute because when you say System.exit 0; the control immediately goes out of the program, and thus finally never executes.