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
31. What is class method ?
A method that is invoked without reference to a particular object. Class methods affect the class as a whole, not a particular instance of the class. Also called a static method. See also instance method.
32. What is class variable ?
A data item associated with a particular class as a whole--not with particular instances of the class. Class variables are defined in class definitions. Also called a static field. See also instance variable.
33. What is classpath ?
An environmental variable which tells the Java virtual machine1 and Java technology-based applications where to find the class libraries, including user-defined class libraries.
34. What is client ?
In the client/server model of communications, the client is a process that remotely accesses resources of a compute server, such as compute power and large memory capacity.
35. What is CODEBASE ?
Works together with the code attribute in the
36. What is comment ?
In a program, explanatory text that is ignored by the compiler. In programs written in the Java programming language, comments are delimited using // or /*...*/.
37. What is commit ?
The point in a transaction when all updates to any resources involved in the transaction are made permanent.
38. What is compilation unit ?
The smallest unit of source code that can be compiled. In the current implementation of the Java platform, the compilation unit is a file.
39. What is compiler ?
A program to translate source code into code to be executed by a computer. The Java compiler translates source code written in the Java programming language into bytecode for the Java virtual machine1. See also interpreter.
40. What is compositing ?
The process of superimposing one image on another to create a single image.