Page 10 - DCAP501_Modern Programming Tools and Techniques I

Unit 1: Introduction to Java

(c) Polymorphism: Polymorphism, which means one name multiple forms, is the ability of a
reference variable to change behavior according to the instance of the object that it holds.
(d) Dynamic binding: It is the method of providing maximum functionality to a program by
resolving the type of object at runtime.
Although the forerunners of Java, like Objective C and C++, fulfill the above four characteristics,
they are not completely object-oriented, because they follow structured programming as well as
object-oriented programming. However, Java is completely object-oriented since everything in
Java is an object.
4. Robust: Java supports some features such as automatic garbage collection, strong memory
allocation, powerful exception handling, and type checking mechanism. The compiler checks the
program for errors and the interpreter checks for any run time errors, thus preventing the system
crash. These features make Java robust.

5. Distributed: The protocols like HTTP and FTP, which are extensively used over the Internet are
developed using Java. Programmers who work on the Internet can call functions with the help of
these protocols and can secure access to the files that are present on any remote machine on the
Internet. This is made possible by writing codes on their local system itself.
6. Portable: The feature ‘write-once run anywhere, anytime’ makes Java portable, provided that the
system has JVM. Java standardizes the data size, irrespective of the operating system or the
processor. These features make Java a portable language.
7. Dynamic: A Java program also includes significant amount of runtime information that is used to
verify and resolve access to objects at runtime. This allows the code to link dynamically in a secure
and appropriate manner.
8. Secure: Memory pointers are not explicitly used in Java. All programs in Java are run under Java
execution environment. Therefore, while downloading an applet program using the Internet, Java
does not allow any virus or other harmful code to access the system as it confines it to the Java
execution environment.
9. Performance: In Java, a program is compiled into an intermediate representation, which is called
Java bytecode. This code can be executed on any system that has a JVM running on it. Earlier
attempts to achieve cross-platform operability accomplished it at the cost of performance. Java
bytecode is designed in such a manner that it is easy to directly translate the bytecode into the
native machine code by using a just-in-time compiler. This helps in achieving high performance.
10. Multithreaded: The primary objective that led to the development of Java was to meet the real-
world requirement of creating interactive and networked programs. In order to accomplish this,
Java provides multithreaded programming, which permits a programmer to write programs that
can do many things simultaneously.
11. Interpreted: Java programs can be directly run from the source code. The source code is read by
the interpreter program and translated into computations. The source code generated is platform
independent. As an interpreted language, Java has an error debugging facility that can trace any
error occurring in the program.
12. Architecture Neutral: Java is also known as an architectural neutral language. In this era of
networks, easy migration of applications to different computer systems having different hardware
architectures and/or operating systems is necessary. The Java compiler generates an object file
format that is architecture neutral. This permits a Java application to execute anywhere on the
network and on many different processors, given the presence of the Java runtime system.
These features of Java have made it a popular programming language.

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