对象
Resources are commonly used to iterate through a mysql or file handle.
example
<?php
while($row = mysql_fetch_row($resource)){
echo $row[0] ;
}
?>
It's possible to fake this treatment.
<?php
class fakewhile{
public $arrayCount;
public $arrayCounter;
function setArrValues(){
$this->arrValues = array(0 =>array("apple","artichoke","apricot"),1 => array("bears","dogs","cats"));
$this->arrayCounter = 0;
$this->arrayCount = count($this->arrValues);
}
function outputValues(){
/*
* Anything until the if statement is evaluted one more
* time then the array count value
*/
$arrayInfo = $this->arrValues;
$arrCounter = $this->arrayCounter;
if($arrCounter > $this->arrayCount){
return false;
}
$endCounter = $arrCounter+1;
$this->arrayCounter = $endCounter;
return $arrayInfo[$arrCounter];
}
}
$fw = new fakewhile();
$fw->setArrValues();
while($row = $fw->outputValues()){
print_r($row);
}
?>
Hopefully will get someone started on completing a complete application.
资源
资源是一种特殊变量，保存了到外部资源的一个引用。资源是通过专门的函数来建立和使用的。所有这些函数及其相应资源类型见附录。
Note: 资源类型是 PHP 4 引进的。
转换为资源
由于资源类型变量保存有为打开文件、数据库连接、图形画布区域等的特殊句柄，因此无法将其它类型的值转换为资源。
释放资源
由于 PHP4 Zend 引擎引进了资源计数系统，可以自动检测到一个资源不再被引用了（和 Java 一样）。这种情况下此资源使用的所有外部资源都会被垃圾回收系统释放。由此原因，很少需要用某些 free-result 函数来手工释放内存。
Note: 持久数据库连接比较特殊，它们不会被垃圾回收系统破坏。参见数据库永久连接一章。
add a note
User Contributed Notes资源
wetmonkey__ at at __gmail dot com
16-Dec-2008 12:17
16-Dec-2008 12:17
adrian dot dziubek at gmail dot com
07-Jul-2008 03:55
07-Jul-2008 03:55
I spent an hour trying to create mock setup for testing SQL queries. The explanation here, that a resource contains file handlers and therefore there is no sense in trying to create one is lame. Being unable to redefine functions, creating a fake resource was the second thing I tried to put test in place, but looking at the search results, I see I'm the first one to try... For me it looks like security by obscurity.
evildictaitor at hotmail dot com
16-Aug-2004 05:25
16-Aug-2004 05:25
In response to yasuo_ohgaki, the reason for the inability of the $_SESSION[] variable to hold references is because a session is just a serialize()'d version of it's member variables saved under a unique filename, with this filename following the user around.
$_SESSION[] is therefore limited by the constraints of the serialize() function
Although this is not <i>strictly</i> true, ($_SESSION does some handling to convert messy variables (e.g. "s and ;s)) it cannot store resources due to the serialise() function's dependancy
isaac at chexbox dot com
22-Jun-2002 08:37
22-Jun-2002 08:37
For the the oblivious: An example of a resource would be a mysql database connection.
$result = mysql_connect("localhost", "username", "pass");
//$result variable is a resource.
print $result;
//will print: Resource ID#1, or something similar