Technical interview questions and answers are essential for any Java Interview because Java is one of the most widely used programming languages in software development. Companies expect candidates to know OOP concepts, multithreading, exceptions, JDBC, collections, and real-time coding questions. Java interviews are commonly part of campus placements and software development roles in companies such as TCS, Infosys, Wipro, Cognizant, and Accenture. For freshers and job seekers, understanding Java concepts clearly makes it easier to clear technical rounds, online coding tests, and project discussions. This guide includes the most important and frequently asked Java interview questions with detailed explanations to help you prepare efficiently. These questions will help you gain confidence during software developer interviews and competitive placement tests.
Java professionals should deepen their expertise through J2EE development concepts and data structures fundamentals
Showing 10 of 301 questions
161. When a thread blocks on I/O, what state does it enter?
A thread enters the waiting state when it blocks on I/O.
162. To what value is a variable of the String type automatically initialized?
The default value of an String type is null.
163. What is the catch or declare rule for method declarations?
If a checked exception may be thrown within the body of a method, the method must
either catch the exception or declare it in its throws clause.
164. What is the difference between a MenuItem and a CheckboxMenuItem?
The CheckboxMenuItem class extends the MenuItem class to support a menu item that
may be checked or unchecked.
165. What is a task's priority and how is it used in scheduling?
A task's priority is an integer value that identifies the relative order in which it should be
executed with respect to other tasks. The scheduler attempts to schedule higher priority
tasks before lower priority tasks.
166. What class is the top of the AWT event hierarchy?
The java.awt.AWTEvent class is the highest-level class in the AWT event-class
hierarchy.
167. When a thread is created and started, what is its initial state?
A thread is in the ready state after it has been created and started.
168. Can an anonymous class be declared as implementing an interface and extending a
class?
An anonymous class may implement an interface or extend a superclass, but may not be
declared to do both.
169. What is the range of the short type?
The range of the short type is -(2^15) to 2^15 - 1.