[Okta Webinar] Learn how to a build a cloud-first strategyRegister Now

x
?
Solved

Efficiency of typecasting

Posted on 2004-09-03
4
Medium Priority
?
446 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 60 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 60 total points
ID: 11971141
objects are still there, you are accessing messages(methods) with different reference.
0
 
LVL 35

Accepted Solution

by:
TimYates earned 60 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

New feature and membership benefit!

New feature! Upgrade and increase expert visibility of your issues with Priority Questions.

Question has a verified solution.

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

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…
Introduction This article is the first of three articles that explain why and how the Experts Exchange QA Team does test automation for our web site. This article explains our test automation goals. Then rationale is given for the tools we use to a…
Viewers will learn about arithmetic and Boolean expressions in Java and the logical operators used to create Boolean expressions. We will cover the symbols used for arithmetic expressions and define each logical operator and how to use them in Boole…
This tutorial will introduce the viewer to VisualVM for the Java platform application. This video explains an example program and covers the Overview, Monitor, and Heap Dump tabs.
Suggested Courses

872 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