Quick question about while loops (Legacy Java Answers Forum)

Legacy Java Answers Forum
November 2001

This page contains an archived post to the Java Answers Forum made prior to February 25, 2002. If you wish to participate in discussions, please visit the new Artima Forums.

Message:

Quick question about while loops

Posted by Hiran on November 20, 2001 at 3:48 AM

If I have a while loop declared the following way:


BufferedReader fileIn = new BufferedReader(new FileReader("c:\\test.txt"));
String taskNumber;
while(!(taskNumber = fileIn.readLine()).equals(null)) {
  //some code
}

what happens if the file test.txt contains nothing in it (ie, taskNumber equals null? As far as I know, it should break from the loop and (in this case) return to the method that called it (since there is nothing after the loop). Yet, it doesn't. It ends the application completely. If test.txt does contain text, then everything continues as normal. Does anyone know what's going on? If you want, I can send you the full code.
Hiran

Replies:

(null).equals(null) ??? Chin Loong November 20, 2001 at 5:27 AM (15)
- Opinions Matt Gerrans November 20, 2001 at 5:50 PM (14)
  - Thnx Hiran November 21, 2001 at 3:55 AM (13)
    - today in the LRT (light rail transit) Chin Loong November 21, 2001 at 6:11 AM (12)
      - Style Matt Gerrans November 21, 2001 at 4:03 PM (11)
        
        Stylin' Matt Gerrans November 21, 2001 at 7:30 PM (10)
        
        south park Chin Loong November 22, 2001 at 7:07 AM (0)
        
        Personal preference Hiran November 22, 2001 at 12:44 AM (8)
        
        mine Chin Loong November 22, 2001 at 6:55 AM (7)
        
        Im with Hiran on this one Jody Brown November 22, 2001 at 12:49 PM (6)
        
        Brace yourself Matt Gerrans November 22, 2001 at 3:10 PM (5)
        
        how can I start to learn java? Ying Chen January 26, 2002 at 12:25 AM (0)
        
        code formatters Jody Brown November 22, 2001 at 5:14 PM (1)
        
        But.... Hiran November 22, 2001 at 9:45 PM (0)
        
        code formatters Jody Brown November 22, 2001 at 5:07 PM (1)
        
        Code Formatter Matt Gerrans November 23, 2001 at 2:32 AM (0)


	Web Artima.com