Dear readers, these Java Interview Questions have been
designed especially to get you acquainted with the nature of questions
you may encounter during your interview for the subject of Java Programming Language.
As per my experience, good interviewers hardly planned to ask any
particular question during your interview, normally questions start with
some basic concept of the subject and later they continue based on
further discussion and what you answer:
Q: What do you know about Java?
A: Java is a high-level programming language originally
developed by Sun Microsystems and released in 1995. Java runs on a
variety of platforms, such as Windows, Mac OS, and the various versions
of UNIX.
Q: What are the supported platforms by Java Programming Language?
A: Java runs on a variety of platforms, such as Windows, Mac
OS, and the various versions of UNIX/Linux like HP-Unix, Sun Solaris,
Redhat Linux, Ubuntu, CentOS, etc.
Q: List any five features of Java?
A: Some features include Object Oriented, Platform Independent, Robust, Interpreted, Multi-threaded
Q: Why is Java Architectural Neutral?
A: It’s compiler generates an architecture-neutral object file
format, which makes the compiled code to be executable on many
processors, with the presence of Java runtime system.
Q: How Java enabled High Performance?
A: Java uses Just-In-Time compiler to enable high performance.
Just-In-Time compiler is a program that turns Java bytecode, which is a
program that contains instructions that must be interpreted into
instructions that can be sent directly to the processor.
Q: Why Java is considered dynamic?
A: It is designed to adapt to an evolving environment. Java
programs can carry extensive amount of run-time information that can be
used to verify and resolve accesses to objects on run-time.
Q: What is Java Virtual Machine and how it is considered in context of Java’s platform independent feature?
A: When Java is compiled, it is not compiled into platform
specific machine, rather into platform independent byte code. This byte
code is distributed over the web and interpreted by virtual Machine
(JVM) on whichever platform it is being run.
Q: List two Java IDE’s?
A: Netbeans, Eclipse, etc.
Q: List some Java keywords(unlike C, C++ keywords)?
A: Some Java keywords are import, super, finally, etc.
Q: What do you mean by Object?
A: Object is a runtime entity and it’s state is stored in
fields and behavior is shown via methods. Methods operate on an object's
internal state and serve as the primary mechanism for object-to-object
communication.
Q: Define class?
A: A class is a blue print from which individual objects are
created. A class can contain fields and methods to describe the behavior
of an object.