Technical interview questions and answers are essential for J2SE Interviews because core Java concepts form the foundation of all Java-based development. Companies test your knowledge of OOP principles, exceptions, packages, JVM architecture, threading, collections, and file handling. These topics commonly appear in placement drives and technical interviews conducted by TCS, Infosys, Wipro, Cognizant, and Capgemini. Understanding J2SE concepts helps freshers and job seekers prepare for both Java developer roles and advanced J2EE/Java EE interviews. This guide features the most commonly asked J2SE interview questions with answers explained in simple language. Preparing these questions will strengthen your Java basics and improve your performance in coding tests and technical rounds.
Java programmers should advance their enterprise skills by studying J2EE frameworks and mastering EJB components for distributed applications
Showing 10 of 237 questions
51. 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.
52. What is definition ?
A declaration that reserves storage (for data) or provides implementation (for methods). See also declaration.
53. What is delegation ?
A declaration that reserves storage (for data) or provides implementation (for methods). See also declaration.
54. What is delegation ?
An act whereby one principal authorizes another principal to use its identity or privileges with some restrictions.
55. 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.
56. What is derived from ?
Class X is "derived from" class Y if class X extends class Y. See also subclass, superclass.
57. What is distributed ?
Running in more than one address space.
58. 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).
59. 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.
60. 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.