Assignment B-7: Write a Java class for finding palindrome

Aim:

Write a Java class for finding palindrome.

Theory:

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. This tutorial gives a complete understanding of Java.

As of December 2008, the latest release of the Java Standard Edition is 6 (J2SE). With the advancement of Java and its widespread popularity, multiple configurations were built to suite various types of platforms. Ex: J2EE for Enterprise Applications, J2ME for Mobile Applications.

Sun Microsystems has renamed the new J2 versions as Java SE, Java EE and Java ME respectively. Java is guaranteed to be Write Once, Run Anywhere.

Java is:

·         Object Oriented: In Java, everything is an Object. Java can be easily extended since it is based on the Object model.

·         Platform independent: Unlike many other programming languages including C and C++, 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.

·         Simple: Java is designed to be easy to learn. If you understand the basic concept of OOP Java would be easy to master.

·         Secure: With Java's secure feature it enables to develop virus-free, tamper-free systems. Authentication techniques are based on public-key encryption.

·         Architectural-neutral: Java 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.

·         Portable: Being architectural-neutral and having no implementation dependent aspects of the specification makes Java portable. Compiler in Java is written in ANSI C with a clean portability boundary which is a POSIX subset.

·         Robust: Java makes an effort to eliminate error prone situations by emphasizing mainly on compile time error checking and runtime checking.

·         Multithreaded: With Java's multithreaded feature it is possible to write programs that can do many tasks simultaneously. This design feature allows developers to construct smoothly running interactive applications.

·         Interpreted: Java byte code is translated on the fly to native machine instructions and is not stored anywhere. The development process is more rapid and analytical since the linking is an incremental and light weight process.

·         High Performance: With the use of Just-In-Time compilers, Java enables high performance.

·         Distributed: Java is designed for the distributed environment of the internet.

·         Dynamic: Java is considered to be more dynamic than C or C++ since 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.

Tools you will need:

·         For performing the examples discussed in this tutorial, you will need a Pentium 200-MHz computer with a minimum of 64 MB of RAM (128 MB of RAM recommended).

You also will need the following software:

·         Linux 7.1 or Windows 95/98/2000/XP operating system.

·         Java JDK 5

·         Microsoft Notepad or any other text editor

      When we consider a Java program it can be defined as a collection of objects that communicate via invoking each other's methods. Let us now briefly look into what do class, object, methods and instance variables mean.

·         Object - Objects have states and behaviors. Example: A dog has states - color, name, breed as well as behaviors -wagging, barking, eating. An object is an instance of a class.

·         Class - A class can be defined as a template/ blue print that describes the behaviors/states that object of its type support.

·         Methods - A method is basically a behavior. A class can contain many methods. It is in methods where the logics are written, data is manipulated and all the actions are executed.

Instance Variables - Each object has its unique set of instance variables. An object's state is created by the values assigned to these instance variables.

Flowchart:

Program:

import java.util.*;

class Palindrome

{

      public static void main(String args[])

     {

         String original, reverse = "";

         Scanner in = new Scanner(System.in);

         System.out.println("Enter a string to check if it is a palindrome");

         original = in.nextLine();

         int length = original.length();

         for ( int i = length - 1; i >= 0; i-- )

             reverse = reverse + original.charAt(i);

         if (original.equals(reverse))

               System.out.println("Entered string is a palindrome.");

         else

               System.out.println("Entered string is not a palindrome.");

      }

}

Conclusion:

Thus we have implemented program for palindrome string.