Re: Does requesting $_SERVER variables need to query the server

On Wed, Feb 23, 2011 at 14:00, Marc Guay <marc.guay@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/