CS58 / CS2309 Java Lab

1.Rational Number Class in Java

AIM:To write a program in Java with the following:(i)Develop a Rational number class.(ii)Use JavaDoc comments for documentation(iii)Your implementation should use efficient representation for a rational number, i.e. (500/1000) should be represented as (1/2).

PROGRAM:

RationalClass.java

import java.util.*;

/***@author Sreekandan.K*/

public class RationalClass{

/**The Numerator part of Rational*/

private int numerator;

/**The Denominator part of Rational*/

private int denominator;/**create and initialize a new Rational object*/

public RationalClass(int numerator,int denominator){if(denominator==0){throw new RuntimeException("Denominator is zero");}int g=gcd(numerator,denominator);if(g==1){System.out.println("No Common Divisor for Numerator and Denominator");this.numerator=numerator;this.denominator=denominator;}else{this.numerator=numerator/g;this.denominator=denominator/g;}}

/**return string representation*/

public String display(){return numerator+"/"+denominator;}

/**@param m@param n@return Greatest common divisor for m and n*/

private static int gcd(int n,int d){if(d==0)return n;elsereturn gcd(d,n%d);}

public static void main(String[] args){Scanner input=new Scanner(System.in);System.out.print("Enter Numerator : ");int numerator=input.nextInt();System.out.print("Enter Denominator : ");int denominator=input.nextInt();Rational rational = new Rational(numerator,denominator);String str=rational.display();System.out.println("Efficient Representation for the rational number :"+str);}}

2.Date Class in Java

AIM:To develop Date class in Java similar to the one available in java.util package.Use JavaDoc comments for documentation.

PROGRAM:

DateFormatDemo.java

import java.text.*;import java.util.*;/***Class DateFormatDemo formats the date and time by using java.text package*@author Sreekandan.K*/public class DateFormatDemo{public static void main(String args[]){/*** @see java.util package*/Date date=new Date();/*** @see java.text package*/DateFormat df;System.out.println("Current Date and Time - Available in java.util Package:");System.out.println("-------------------------------------------------------");System.out.println(date);System.out.println();System.out.println("Formatted Date - Using DateFormat Class from java.text Package:");System.out.println("---------------------------------------------------------------");df=DateFormat.getDateInstance(DateFormat.DEFAULT);System.out.println("Default Date Format:"+df.format(date));df=DateFormat.getDateInstance(DateFormat.SHORT);System.out.println("Date In Short Format:"+df.format(date));df=DateFormat.getDateInstance(DateFormat.MEDIUM);System.out.println("Date In Medium Format:"+df.format(date));df=DateFormat.getDateInstance(DateFormat.LONG);System.out.println("Date In Long Format:"+df.format(date));df=DateFormat.getDateInstance(DateFormat.FULL);System.out.println("Date In Full Format:"+df.format(date));System.out.println();System.out.println("Formatted Time - Using DateFormat Class from java.text Package:");System.out.println("---------------------------------------------------------------");df=DateFormat.getTimeInstance(DateFormat.DEFAULT);System.out.println("Default Time Format:"+df.format(date));df=DateFormat.getTimeInstance(DateFormat.SHORT);System.out.println("Time In Short Format:"+df.format(date));df=DateFormat.getTimeInstance(DateFormat.MEDIUM);System.out.println("Time In Medium Format:"+df.format(date));df=DateFormat.getTimeInstance(DateFormat.LONG);System.out.println("Time In Long Format:"+df.format(date));df=DateFormat.getTimeInstance(DateFormat.FULL);System.out.println("Time In Full Format:"+df.format(date));System.out.println();System.out.println("Formatted Date and Time - Using SimpleDateFormat Class from java.text Package:");System.out.println("------------------------------------------------------------------------------");/*** @see java.text package*/SimpleDateFormat sdf;sdf=new SimpleDateFormat("dd MMM yyyy hh:mm:sss:S E w D zzz");System.out.println(sdf.format(date));}}

3.Lisp-like List in Java

AIM:To implement Lisp-like list in Java that performs the basic operations such as 'car', 'cdr', and 'cons'.

PROGRAM:

LispOperation.java

import java.util.*;/***@author Sreekandan.K*/class Lisp{public Vector car(Vector v){Vector elt=new Vector();elt.addElement(v.elementAt(0));return elt;}public Vector cdr(Vector v){Vector elt=new Vector();for(int i=1;i