[PHP] Does requesting $_SERVER variables need to query the server
This question will probably reveal my lacking knowledge of the fundamentals, but I'm a go for it anyway: When you use a $_SERVER variable, is a query made to the server to get the information or is it just sitting in a variable all ready to go? Reworded, is there any efficiency gained by storing the data in a local variable if it's going to be used many times in the script? My experience with jQuery has taught me to store $(objects) in local variables if they're going to be used repeatedly because the DOM is queried every time a jQuery object is generated, so I'm wondering if a similar logic applies. Example: if ($_SERVER['SCRIPT_NAME'] == 'how.php') // do stuff if ($_SERVER['SCRIPT_NAME'] == 'why.php') // do other stuff vs. $script_name = $_SERVER['SCRIPT_NAME']; if ($script_name == 'how.php') // do stuff if ($script_name == 'why.php') // do other stuff Cheerios, Marc -- PHP General Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php
Re: [PHP] Does requesting $_SERVER variables need to query the server
Marc, $_SERVER is an array and it should have all the information. I do not know the answer for the latter part of your query. Regards, Shreyas On Thu, Feb 24, 2011 at 12:30 AM, Marc Guay marc.g...@gmail.com wrote: This question will probably reveal my lacking knowledge of the fundamentals, but I'm a go for it anyway: When you use a $_SERVER variable, is a query made to the server to get the information or is it just sitting in a variable all ready to go? Reworded, is there any efficiency gained by storing the data in a local variable if it's going to be used many times in the script? My experience with jQuery has taught me to store $(objects) in local variables if they're going to be used repeatedly because the DOM is queried every time a jQuery object is generated, so I'm wondering if a similar logic applies. Example: if ($_SERVER['SCRIPT_NAME'] == 'how.php') // do stuff if ($_SERVER['SCRIPT_NAME'] == 'why.php') // do other stuff vs. $script_name = $_SERVER['SCRIPT_NAME']; if ($script_name == 'how.php') // do stuff if ($script_name == 'why.php') // do other stuff Cheerios, Marc -- PHP General Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php -- Regards, Shreyas Agasthya
Re: [PHP] Does requesting $_SERVER variables need to query the server
On Wed, Feb 23, 2011 at 14:00, Marc Guay marc.g...@gmail.com wrote: This question will probably reveal my lacking knowledge of the fundamentals, but I'm a go for it anyway: When you use a $_SERVER variable, is a query made to the server to get the information or is it just sitting in a variable all ready to go? Reworded, is there any efficiency gained by storing the data in a local variable if it's going to be used many times in the script? My experience with jQuery has taught me to store $(objects) in local variables if they're going to be used repeatedly because the DOM is queried every time a jQuery object is generated, so I'm wondering if a similar logic applies. $_SERVER is just a prepopulated superglobal array that is created at runtime. When the script is executed via the web, PHP and the web server (for example, Apache) generate numerous environment values as directed by their configuration. The quickest way to learn about this in more detail is to use it's nickname in Google: EGPCS. The actual configuration directive is variables_order, but many folks - particularly the PHP3/4 and very early PHP5 - will be more familiar with the nickname, which is an acronym for the default order of superglobals: Environment, Get, Post, Cookie, Server. -- /Daniel P. Brown Dedicated Servers, Cloud and Cloud Hybrid Solutions, VPS, Hosting (866-) 725-4321 http://www.parasane.net/ -- PHP General Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php
Re: [PHP] Does requesting $_SERVER variables need to query the server
$_SERVER is just a prepopulated superglobal array that is created at runtime. Thanks for the clear answer. Marc -- PHP General Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php
Re: [PHP] Does requesting $_SERVER variables need to query the server
so when you're using $_SERVER variables there's no call back to the server, as the code is still being run on the server at that point. This is something I actually do understand. I was wondering if the code running on the server had to query the server for the information every time a $_SERVER var was referenced, but like Daniel explained, the contents of the $_SERVER array are populated at runtime and so no further hey server, what version of apache are you running? questions need to be asked of it. Marc -- PHP General Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php
