J2SE Interview Questions with Answers 4

What is default ?
A Java keyword optionally used after all case conditions in a switch statement. If all case conditions are not matched by the value of the switch variable, the default keyword will be executed.

What is definition ?
A declaration that reserves storage (for data) or provides implementation (for methods). See also declaration.

What is delegation ?
An act whereby one principal authorizes another principal to use its identity or privileges with some restrictions.

What is deprecation ?
Refers to a class, interface, constructor, method or field that is no longer recommended, and may cease to exist in a future version.

What is derived from ?
Class X is "derived from" class Y if class X extends class Y. See also subclass, superclass.

What is distributed ?
Running in more than one address space.

What is distributed application ?
An application made up of distinct components running in separate runtime environments, usually on different platforms connected through a network. Typical distributed applications are two-tier (client/server), three-tier (client/middleware/server), and n-tier (client/multiple middleware/multiple servers).

What is do ?
A Java keyword used to declare a loop that will iterate a block of statements. The loop's exit condition can be specified with the while keyword.

What is DOM ?
Document Object Model. A tree of objects with interfaces for traversing the tree and writing an XML version of it, as defined by the W3C specification.

What is double ?
A Java keyword used to define a variable of type double.

What is double precision ?
In the Java programming language specification, describes a floating point number that holds 64 bits of data. See also single precision.

What is DTD ?
Document Type Definition. A description of the structure and properties of a class of XML files.

What is else ?
A Java keyword used to execute a block of statements in the case that the test condition with the if keyword evaluates to false.

What is Embedded Java Technology ?
The availability of Java 2 Platform, Micro Edition technology under a restrictive license agreement that allows a licensee to leverage certain Java technologies to create and deploy a closed-box application that exposes no APIs.

What is encapsulation ?
The localization of knowledge within a module. Because objects encapsulate data and implementation, the user of an object can view the object as a black box that provides services. Instance variables and methods can be added, deleted, or changed, but as long as the services provided by the object remain the same, code that uses the object can continue to use it without being rewritten. See also instance variable, instance method.

What is enum ?
A Java keyword used to declare an enumerated type.

What is enumerated type ?
A type whose legal values consist of a fixed set of constants.