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2 questions: One on arrays, the other on clearing the screen.

Posted on 2003-11-19
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Last Modified: 2010-03-31
Hi, I have two questions that I need to be answered involving java.
1.  Is it possible to expand an array after it has been initiated?  If so, how?
2.  I need to clear the screen and I'm not too familiar with classes, so I don't know how to incorporate much GUI or graphics.  How can I do this?
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Question by:MarkThompson417
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by:jimmack
ID: 9780998
1. No.  You would have to create another array of the size you require, then copy the original array contents across.

2. Clear the screen in what way?  If you have a text area or text field, you can usually use a method like setText("") to clear the content.
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jimmack earned 20 total points
ID: 9781013
If you need an array that is expandable, you should use a java.util.ArrayList.

You can access it's entries using and index (starting at 0) if you want:

ArrayList al = new ArrayList();
al.add("First");
al.add("Second");
al.add("Third");

System.out.println((String)al.get(2));

Or, more usually with ArrayLists, you would "iterate" through it, using:

Iterator it = al.iterator();
while (it.hasNext())
{
    String content = (String)it.next();
}
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Expert Comment

by:jimmack
ID: 9781037
There are several alternatives to an ArrayList, including, but not limited to:  Vector, LinkedList, Hashtable...

Each provides different facilities, so you'll need to look at the javadocs to decide what you actually need.  eg. a Vector is the same as an ArrayList, but it is thread safe.  Hashtables store key-value pairs (both Objects), etc.
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Expert Comment

by:TimYates
ID: 9781115
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