V22.0101 ......Homework Assignment 1 Draft #2 ...... Fall 2006
Binary Representation of Numbers
Assigned: MON, FEB 5.
First Version Due (by email to etutor):
(Marateck) THURS, FEB 8, at 11:59 pm
Rewrite your first draft so that a class called
Binary stores the decimal number in the instance variable
numVal and the binary string corresponding to numVal will be
stored in the instance variable binStr. The value of the decimal number
is passed by the driver class Hw1 to the constructor. The constructor
has the heading
public Binary(int num) and will assign num to numVal. .
The class Binary will have the same two methods you have already written for
draft #1. They now have the following form:
You can "hard-wire" the example numbers into the main method, or you can read
them from the the keyboard using the JOptionPane class described in the text
book (page 45) or the Scanner class (p53 in text, or see the
instructions for the first draft)
. The simplest form to use for assigning input to a string using
JOptionPane, let's say number is String number =
JOptionPane.showInputDialog("Type your decimal number");. If you have JDK
1.5 (and I urge you to download it), use the Scanner class.
- public void getBin(). This produces the string consisting of the
binary equivalent of numVal and assigns it to the instance variable
- public boolean checkBin()). This take the binary string in
binStr and checks to see if it correctly represents the number in
numVal. If it does, it returns true to the driver class, Hw1, else it
- public String getBinValue() This returns the binary number.
The main method in Hw1should
check to make sure the decimal value is between 0 and 255. If it is not, it
should print an informative error message (using System.out.println) and store
the number 0 instead.