?
Solved

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

Posted on 2003-11-19
4
Medium Priority
?
250 Views
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?
0
Comment
Question by:MarkThompson417
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
  • 3
4 Comments
 
LVL 15

Expert Comment

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.
0
 
LVL 15

Accepted Solution

by:
jimmack earned 80 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();
}
0
 
LVL 15

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.
0

Featured Post

Optimize your web performance

What's in the eBook?
- Full list of reasons for poor performance
- Ultimate measures to speed things up
- Primary web monitoring types
- KPIs you should be monitoring in order to increase your ROI

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

INTRODUCTION Working with files is a moderately common task in Java.  For most projects hard coding the file names, using parameters in configuration files, or using command-line arguments is sufficient.   However, when your application has vi…
Introduction This article is the last of three articles that explain why and how the Experts Exchange QA Team does test automation for our web site. This article covers our test design approach and then goes through a simple test case example, how …
Viewers learn about the third conditional statement “else if” and use it in an example program. Then additional information about conditional statements is provided, covering the topic thoroughly. Viewers learn about the third conditional statement …
Viewers will learn one way to get user input in Java. Introduce the Scanner object: Declare the variable that stores the user input: An example prompting the user for input: Methods you need to invoke in order to properly get  user input:
Suggested Courses
Course of the Month13 days, 18 hours left to enroll

800 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question