File APIs for Java Developers
Manipulate DOC, XLS, PPT, PDF and many others from your application.
http://aspose.com/file-tools
The moose likes Java in General and the fly likes about this array class Big Moose Saloon
  Search | Java FAQ | Recent Topics | Flagged Topics | Hot Topics | Zero Replies
Register / Login


Win a copy of Spring in Action this week in the Spring forum!
JavaRanch » Java Forums » Java » Java in General
Bookmark "about this array class" Watch "about this array class" New topic
Author

about this array class

Tom Chot
Greenhorn

Joined: Oct 13, 2003
Posts: 2
Hello,
i know that i am not supposed to ask this kind of question
but i don't really know how to fix the error in this below code.
--------------------------------------------------------------------
import java.io.*;
class testArray
{
boolean check = true;
String[] c;
String[] read;
BufferedReader b = new BufferedReader(new InputStreamReader(System.in));
int i = 0;

public static void main(String [] args)
{
int[] dog;

while(check == true)
{

System.out.println("Type anything : ");
read[i] = b.readLine();
System.out.println("more? :");
c[i] = b.readLine();

if((c.charAt(0) == 'n') || (c.charAt(0) == 'N'))
{
check = false;
}
else
{
check = true;
}


}

for(int j = 0; j < read.length() ; j++)
{
System.out.println("name: " + read[j]);
}
}
}
----------------------
Very Very thx and really appreciate..
Regards,
TOm
Ernest Friedman-Hill
author and iconoclast
Marshal

Joined: Jul 08, 2003
Posts: 24187
    
  34

Hi Tom,
Welcome to JavaRanch!
The most obvious problem with this program is that "read" is a null reference; you haven't allocated an array for it to point to, so when you try to use it, you get a NullPointerException. So you need to allocate some space, like

As soon as you do allocate a fixed-sized array, you'll have the problem that the user may type in more lines of text than there are array elements, and the you'll get ArrayIndexOutOfBoundsException; for this reason, you should consider changing this program to use a java.util.ArrayList instead of a raw array.


[Jess in Action][AskingGoodQuestions]
Tom Chot
Greenhorn

Joined: Oct 13, 2003
Posts: 2
in this code..
i wanna use the dynamic array so that i don't need to worry about the size of the array?
Regards,
Tom
Stefan Wagner
Ranch Hand

Joined: Jun 02, 2003
Posts: 1923

Originally posted by Tom Chot:

String[] c;
String[] read;
c[i] = b.readLine();

if((c.charAt(0) == 'n') || (c.charAt(0) == 'N'))

instead of

try


http://home.arcor.de/hirnstrom/bewerbung
 
I agree. Here's the link: http://aspose.com/file-tools
 
subject: about this array class