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
91. What is the Locale class?
The Locale class is used to tailor program output to the conventions of a particular geographic, political, or cultural region .
92. What is the Map interface?
The Map interface replaces the JDK 1.1 Dictionary class and is used associate keys with values.
93. What is the purpose of finalization?
The purpose of finalization is to give an unreachable object the opportunity to perform any cleanup processing before the object is garbage collected.
94. What is the purpose of garbage collection in Java, and when is it used?
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.
95. What is the Set interface?
The Set interface provides methods for accessing the elements of a finite mathematical set. Sets do not allow duplicate elements.
96. What is the SimpleTimeZone class?
The SimpleTimeZone class provides support for a Gregorian calendar .
97. What is the typical use of Hashtable?
Whenever a program wants to store a key value pair, one can use Hashtable.
98. What is the Vector class?
The Vector class provides the capability to implement a growable array of objects.
99. What method must be implemented by all threads?
All tasks must implement the run() method, whether they are a subclass of Thread or implement the Runnable interface.
100. What modifiers are allowed for methods in an Interface?
Only public and abstract modifiers are allowed for methods in interfaces.