Actual Date to Day of the Week Application

[bcheath_1]

I have been using JAVA for a whole two weeks now. I am enrolled in CSC 148 at my local college.

I am supposed to write a program that asks the user for his or her age and replies with the day of the week on which he or she was born.

I am familiar with the I/O, but cannot figure out to convert from a date
(ie. 07/04/1776) to a day (ie. Saturday).

Here is my current code:

/*
     Ask the user for his or her birthdate and return with the day of the week
     on which he or she was born.
*/

import javax.swing.*;
import java.sql.*;  //For Return Date

class Exercise2_29 {

     public static void main( String[] args ) {

          //Input user birth date
          String          bdate;

          bdate = JOptionPane.showInputDialog(null, "What is your birth date?
                                                                    (MM/DD/YYYY)");

          //Convert user birth date to day of week

     }
}

Note: I can only use the java.util or java.sql classes. The GregorianCalendar class has not yet been officially taught and, therefore, can't be used.

Also, is the code I currently have good. Do I need to import any other classes, or add any more strings?

Thanks in advance for any help.

bcheath_1

[jwenting]

install the API docs.
Look up DateFormat, SimpleDateFormat, java.util.Date, and Calendar.
Using those you can do what you want quite easily.

[rachawal]

I'm a newbie, also, trying to figure out the same problem...and I'm still trying to figure out just how to use DateFormat, SimpleDateFormat, java.util.Date, and Calendar. It seems that the original post was trying to get an example of how you programatically determine the day of the week that a person was born on...Could someone provide a basic example of this?

Thanks,

[Gink]

count the days in between current date and that date, subtract it, mod it by 7

[jwenting]

nah. Plug the date into a Calendar and get the correct field out of it...
Something like

Calendar calendar = new GregorianCalendar();
calendar.setTime(birthdate);
int dayOfBirth = calendar.get(Calendar.DAY_OF_WEEK);

The biggest mistake many beginners in Java (or most languages) seem to make is to not study the standard library.
It contains a TON of very handy utility classes that can really make your life easy.