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
91. What is identifier ?
The name of an item in a program written in the Java programming language.
92. What is IIOP ?
Internet Inter-ORB Protocol. A protocol used for communication between CORBA object request brokers.
93. What is if ?
A Java keyword used to conduct a conditional test and execute a block of statements if the test evaluates to true.
94. What is impersonation ?
An act whereby one entity assumes the identity and privileges of another entity without restrictions and without any indication visible to the recipients of the impersonator's calls that delegation has taken place. Impersonation is a case of simple delegation.
95. What is implements ?
A Java keyword included in the class declaration to specify any interfaces that are implemented by the current class.
96. What is import ?
A Java keyword used at the beginning of a source file that can specify classes or entire packages to be referred to later without including their package names in the reference.
97. What is inheritance ?
The concept of classes automatically containing the variables and methods defined in their super types. See also super class, subclass.
98. What is instance ?
An object of a particular class. In programs written in the Java programming language, an instance of a class is created using the new operator followed by the class name.
99. What is instance method ?
Any method that is invoked with respect to an instance of a class. Also called simply a method. See also class method.
100. What is instance variable ?
Any item of data that is associated with a particular object. Each instance of a class has its own copy of the instance variables defined in the class. Also called a field. See also class variable.