I think Sujit is right... The String a = "aa"; does absolutely nothing apart from
creating a new String reference 20000 times. I would expect the compiler to indicate
something...
14/12/2001 10:35:10, Sujit <[EMAIL PROTECTED]> wrote:
>Is this the actual code you tested and got the output ...
>or
>instead of the line String a = "aa";
>you had some other code ??
>
>actually, String a = "aa"; even if you loop does nothing ...
>
>I think both the for loop will not be executed at all ...
>
>the JVM should optimises the code ...
>and the time should be same ...
>
>BTW your second code snippet should be faster than the first one ...
>
>
>----- Original Message -----
>From: "ShriKant Vashishtha" <[EMAIL PROTECTED]>
>To: <[EMAIL PROTECTED]>
>Sent: Friday, December 14, 2001 5:14 AM
>Subject: Re: OffBeat question...Java performance.
>
>
>> Hi,
>>
>> I apologise for the mistake. You are right. Please find the currect
>> snippets.
>>
>> String [] arrayStr = new String[20000];
>> System.out.println(System.currentTimeMillis());
>> for(i=0;i<arrayStr.length;i++){
>> String a="aa";
>> }
>> System.out.println(System.currentTimeMillis());
>>
>> Output:
>> 1008319728796
>> 1008319728799
>>
>> String [] arrayStr = new String[20000];
>> int length = arrayStr.length;
>> System.out.println(System.currentTimeMillis());
>> for(i=0;i<length;i++){
>> String a="aa";
>> }
>> System.out.println(System.currentTimeMillis());
>>
>> Output:
>> 1008319767200
>> 1008319767221
>>
>> Regards,
>> -ShriKant
>>
>> A mailing list about Java Server Pages specification and reference wrote:
>>
>> > From: Sujit <[EMAIL PROTECTED]>@JAVA.SUN.COM on 12/14/2001 04:51 AM
>EST
>> >
>> > Please respond to A mailing list about Java Server Pages specification
>> and
>> > reference <[EMAIL PROTECTED]>
>> >
>> > To: [EMAIL PROTECTED]
>> > cc:
>> > Subject: Re: OffBeat question...Java performance.
>> >
>> > what is the difference between both the code ..
>> >
>> > I don't see any difference between the code
>> > that is embedded between the system.out's
>> >
>> > am I missing something ??
>> >
>> > ----- Original Message -----
>> > From: "ShriKant Vashishtha" <[EMAIL PROTECTED]>
>> > To: <[EMAIL PROTECTED]>
>> > Sent: Friday, December 14, 2001 4:34 AM
>> > Subject: OffBeat question...Java performance.
>> >
>> > > Hi,
>> > >
>> > > I am trying to judge the performance impact of the following Java
>code.
>> > >
>> > > String [] arrayStr = new String[20000];
>> > > System.out.println(System.currentTimeMillis());
>> > > for(i=0;i<arrayStr.length;i++){
>> > > String a="aa";
>> > > }
>> > > System.out.println(System.currentTimeMillis());
>> > >
>> > > Output:
>> > > 1008319728796
>> > > 1008319728799
>> > >
>> > > String [] arrayStr = new String[20000];
>> > > int length = arrayStr.length;
>> > > System.out.println(System.currentTimeMillis());
>> > > for(i=0;i<arrayStr.length;i++){
>> > > String a="aa";
>> > > }
>> > > System.out.println(System.currentTimeMillis());
>> > >
>> > > Output:
>> > > 1008319767200
>> > > 1008319767221
>> > >
>> > > In my view the first code stub should have been faster as in the
>second
>> > > snippet we are getting an overhead of a instance variable call over an
>> > > String [] object compared to the length already computed in the first
>> > > one. What is happening behind the scene, I am not aware. Could
>somebody
>> > > please explain.
>> > >
>> > > Thanks,
>> > > -ShriKant
>> > >
>> > >
>> >
>>
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__________________________________________
"It can only be attributed to human error"
2001 A Space Odyssey
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