Beginning java programming in a course from home

Question

hi, i've recently started working on a java course, learning from home and am a bit stuck on what it all means really as my level of english isnt very good.
it says i have to write a class to represent a calendar date, and then write a program that instantiates 2 of these date objects, initializes their member variables and print them out.
Would someone please be abel to help me with an example of this,
I would be so grateful!!!
from
waynemorgan86

Answer 1

not compiled... not unit tested... but commented to the beejeepers.
//DateStringExample is an example of a simple java class. It creates two dates,
//initialises their member variables, and prints both values.
class DateStringExample
     //the DateString class encapsulates all the variables and methods which
     //enable is to store a date as a String, and retrieve it again.
     private String DateString {
          //a "member" variable... note that it is private meaning that it is
          //visible only within the DateString class... so other classes can't
          //see it, allowing you to restrict access to this value, and validate
          //value when it is "stored".
          private String date;
          //a default contructor ("no arg" constructor) nb: if you don't
          //specify a default contructor java creates an empty one for you.
          DateString() {
               //set the value of the date variable in this instance of the DateString
               //class to todays date, which is the default value of a Date object.
               this.date = (new Date).toString;
          //a "setter contructor" allows you to create a new DateString and
          //set it's value in one easy move.
          DateString(String date) throws Exception {
               setDate(date);
          //a "setter" validates the supplied value and sets the member variable.
          void setDate(String date) throws Exception {
               if (date = null) throw Exception("null date");
               try {
                    Date tmp = DateFormat.parse(date);
               } catch ( ParseException e ) {
                    throw new Exception("invalid date " + date, e);
               this.date = date;
          //a "getter" returns the current value of the member variable.
          DateString getDate() {
               return(this.date);
     //this is the special main method which java run's automatically when
     //you run the "program"
     public static void main(String[] argv)
          try {
               //get me an instance of a DateString called today, which contains
               //todays date (as a string);
               DateString today = new DateString();
               //get me another instance of a DateString called today, which contains
               //tomorrowsa date
               DateString tomorrow = new DateString("2006-09-20 12:46:00");
               //output the two values
               System.out.println("today is "+today+" and tomorrow is "+tomorrow);
               //try to set tommorow to an invalid date, and print again
               tomorrow.setDate("2006-02-31 00:00:00");
               System.out.println("today is "+today+" and tomorrow is "+tomorrow);
          //catch any errors, and just report them to the standard error stream.
          } catch (Exception e) {
               System.err.println(e);
//NOTES:
//* This whole class is obviously a complete waste of time, except as
//      a simple example of a class to newbie java programmers.
//* The Java language provides a rich featured set of classes for date manipulation.//and a few obvious bugs... hand this in as is and you will fail.
corlettk: removed dodgy BadDateStringException, I think.