在PHP中，我假设每个对象都是引用，但在这段代码中；
/**
* adds a master object which affects browse and insert operations
*
* @param 'bk'dataset'master|string $cursor
* @param Array $fields
*/
function SetMasterCursor ($cursor, $fields)
{
if (is_object($cursor)) {
$this->master = & $cursor; /** !!!!!! **/
} elseif (is_string($cursor)) {
$this->master = 'bk'dataset'master::instance($cursor, null, $this->GetModuleName());
}
$this->_masterfld = $fields;
}
我需要强制PHP使用带有&运算符（$this->master = & $cursor）的引用。如果我不使用运算符，它的行为会很奇怪。它正在调用游标类的构造函数。很明显，这不仅仅是复制参考文献。我想，从PHP5到$object1 = $object2和$object1 = & $object2是一样的，只是其他类型（字符串等）不同。我觉得我的假设是错误的。
这里将对此进行详细解释：http://php.net/manual/en/language.oop5.references.php
通过"default"或通过<reference"> 我认为（上一页的）以下代码表明了这一点： （如果你问我的话，这很难看，但事实就是这样；））。<?php
class Foo {
private static $used;
private $id;
public function __construct() {
$this->id = self::$used++;
}
public function __clone() {
$this->id = self::$used++;
}
}
$a = new Foo; // $a is a pointer pointing to Foo object 0
$b = $a; // $b is a pointer pointing to Foo object 0, however, $b is a copy of $a
$c = &$a; // $c and $a are now references of a pointer pointing to Foo object 0
$a = new Foo; // $a and $c are now references of a pointer pointing to Foo object 1, $b is still a pointer pointing to Foo object 0