Solved

Efficiency of typecasting

Posted on 2004-09-03
4
413 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

PRTG Network Monitor: Intuitive Network Monitoring

Network Monitoring is essential to ensure that computer systems and network devices are running. Use PRTG to monitor LANs, servers, websites, applications and devices, bandwidth, virtual environments, remote systems, IoT, and many more. PRTG is easy to set up & use.

Question has a verified solution.

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

Suggested Solutions

Title # Comments Views Activity
Application launch issue with Apache Tomcat 5 44
starter POM and spring-boot-starter,  spring-boot-web 2 54
xampp tool 12 50
how to install java on RHEL image on EC2 4 27
Are you developing a Java application and want to create Excel Spreadsheets? You have come to the right place, this article will describe how you can create Excel Spreadsheets from a Java Application. For the purposes of this article, I will be u…
Java Flight Recorder and Java Mission Control together create a complete tool chain to continuously collect low level and detailed runtime information enabling after-the-fact incident analysis. Java Flight Recorder is a profiling and event collectio…
Viewers will learn about the regular for loop in Java and how to use it. Definition: Break the for loop down into 3 parts: Syntax when using for loops: Example using a for loop:
This video teaches viewers about errors in exception handling.

772 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