note 44841 deleted from function.require-once by aidan
| From: | aidan@php.net | Date: | Wed, 18 Aug 2004 06:25:08 +0000 |
| Subject: | note 44841 deleted from function.require-once by aidan | ||
| References: | 1 | Groups: | php.notes |
| Request: | Send a blank email to php-notes+get-74857@lists.php.net to get a copy of this message | ||
Note Submitter: Tolan (tolan at overtops dot org)
----
As far as I can tell this is not entirely true:
---
The require_once() statement includes and evaluates the specified file during the execution of the
script. This is a behavior similar to the require() statement, with the only difference being that
if the code from a file has already been included, it will not be included again. See the
documentation for require() for more information on how this statement works.
---
Take two files:
bar.php:
<?php
class Bar{
function bar(){
require_once('foo.php');
}
}
$a = new Bar();
$a->Bar();
$b = new Foo();
echo $b->test();
?>
foo.php:
<?php
class Foo{
function test(){
return "Everything worked.";
}
}
?>
If you execute bar.php, then with require_once() it will parse foo.php as if it had been included or
required outside of the method Bar::bar(), allowing you to work with Foo and Bar classes normally.
However if you use include() or require() instead of include_once() or require_once(), then you will
get the following error (in PHP5):
Fatal error: Cannot redeclare class Foo in foo.php on line 3