Re: How to assign eval() to variable?
| From: | Stuart | Date: | Sat, 23 May 2009 14:34:00 +0000 |
| Subject: | Re: How to assign eval() to variable? | ||
| References: | 1 2 3 4 5 6 | Groups: | php.general |
| Request: | Send a blank email to php-general+get-293024@lists.php.net to get a copy of this message | ||
2009/5/23 Robert Cummings <robert@interjinn.com>:
> On Sat, 2009-05-23 at 15:11 +0100, Stuart wrote:
>> 2009/5/23 Robert Cummings <robert@interjinn.com>:
>> > On Sat, 2009-05-23 at 14:43 +0100, Stuart wrote:
>> >> 2009/5/23 Afan Pasalic <afan@afan.net>:
>> >> > short hack works like a charm!
>> >> > :-)
>> >>
>> >> It may work but output buffers are relatively expensive. The eval
>> >> function will return the value the eval'd code returns, so just stick
>> >> a return statement at the end of the string you're eval'ing.
>> >
>> > Where di you hear that output buffers are expensive? I have found the
>> > following:
>> >
>> > <?php
>> >
>> > ob_start();
>> >
>> > for( $i = 0; $i < 10000000; $i++ )
>> > {
>> > echo 'blaaaaaaaaaaaaaaaaaaaaaaaaaah';
>> > }
>> >
>> > $foo = ob_get_contents();
>> > ob_end_clean();
>> >
>> > ?>
>> >
>> > To consistently be faster than the following:
>> >
>> > <?php
>> >
>> > for( $i = 0; $i < 10000000; $i++ )
>> > {
>> > $foo .= 'blaaaaaaaaaaaaaaaaaaaaaaaaaah';
>> > }
>> >
>> > ?>
>> >
>> > However, if I do the following:
>> >
>> > <?php
>> >
>> > for( $i = 0; $i < 10000000; $i++ )
>> > {
>> > ob_start();
>> > echo 'blaaaaaaaaaaaaaaaaaaaaaaaaaah';
>> > $foo .= ob_get_contents();
>> > ob_end_clean();
>> > }
>> >
>> > ?>
>> >
>> > The run-time is approximately 3 times slower... not exactly expensive
>> > considering it incorporates the concatenation as well as the output
>> > buffering.
>>
>> Context is everything Rob.
>>
>> I said *relatively* expensive because the comparison was between using
>> an output buffer to capture a value from a call to eval compared to
>> simply returning the value from the eval'd code.
>
> You should have connected your phrasing to context then. Your wording
> suggested a generalization. "Relatively expensive" did not relate to any
> other information you provided in the same sentence... relatively
> expensive to what? It was in the first sentence, before you introduced
> information about returning directly from the eval statement.
> Information linkage is important, as is chronology.
Looking back at what I wrote I agree that I could have made it
clearer. The context I was relying on from the message I was replying
to did not adequately frame my comment.
-Stuart
--
http://stut.net/