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
Solved

Efficiency of typecasting

Posted on 2004-09-03
4
417 Views
Last Modified: 2011-10-03
Hi All,

I just get the doubt. Could you please clarify that

java.util.List contains either strings or my own defined class instances

now when I try to type cast them to Array, will it reduce the efficiency of method??


I  am type casting like this. List's size may vary from 1 to 100000

(String[])list.toArray(new String[0]);  

        or

(IWdHttpRefernce[])list.toArray(new IWdHttpRefernce[0]);  

0
Comment
Question by:sudhakar_koundinya
  • 2
4 Comments
 
LVL 9

Assisted Solution

by:DrWarezz
DrWarezz earned 20 total points
ID: 11971117
:o\ Don't think so..
[r.D]
0
 
LVL 6

Expert Comment

by:expertmb
ID: 11971134
>>will it reduce the efficiency of method??
it should not, you are now making different kind of reference to the object.
0
 
LVL 6

Assisted Solution

by:expertmb
expertmb earned 20 total points
ID: 11971141
objects are still there, you are accessing messages(methods) with different reference.
0
 
LVL 35

Accepted Solution

by:
TimYates earned 20 total points
ID: 11971214
> now when I try to type cast them to Array, will it reduce the efficiency of method??

toArray does this:

    public Object[] toArray(Object a[])
    {
        if (a.length < size)
            a = (Object[])java.lang.reflect.Array.newInstance( a.getClass().getComponentType(), size );
      System.arraycopy(elementData, 0, a, 0, size);
        if (a.length > size)
            a[size] = null;
        return a;
    }

But then, you will be accessing items in an array directly, rather than calling a method (which accesses elements in an array directly) ;-)

The difference will be minimal (at most) ;-)
0

Featured Post

Free Tool: Path Explorer

An intuitive utility to help find the CSS path to UI elements on a webpage. These paths are used frequently in a variety of front-end development and QA automation tasks.

One of a set of tools we're offering as a way of saying thank you for being a part of the community.

Question has a verified solution.

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

Suggested Solutions

Title # Comments Views Activity
Oracle SQL syntax check  without executing 6 74
jboss 7.1 start up error 1 33
Java program running SQL query 5 37
Running JavaFX on the Raspberry Pi 27 39
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…
For beginner Java programmers or at least those new to the Eclipse IDE, the following tutorial will show some (four) ways in which you can import your Java projects to your Eclipse workbench. Introduction While learning Java can be done with…
Viewers learn about the scanner class in this video and are introduced to receiving user input for their programs. Additionally, objects, conditional statements, and loops are used to help reinforce the concepts. Introduce Scanner class: Importing…
This tutorial covers a step-by-step guide to install VisualVM launcher in eclipse.

856 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