在PHP 5中，$ obj1 = $ obj2与$ obj1 =& $ obj2的 [英] in PHP 5, $obj1 = $obj2 not the same as $obj1 =& $obj2
问题描述
似乎在PHP 5中，$ obj1 = $ obj2与$ obj1 =& $ obj2
虽然手册说...
http://www.php.net/manual/en/languag...assignment.php
seems like in PHP 5, $obj1 = $obj2 is not the same as $obj1 =& $obj2
although the manual says...
http://www.php.net/manual/en/languag...assignment.php
从PHP 4开始，支持按引用分配，
使用$ var =& $ othervar
Since PHP 4, assignment by reference has been supported,
using the $var = &$othervar
从PHP 5起，对象通过引用分配
，除非明确告知新的克隆
关键字。
As of PHP 5, objects are assigned by reference
unless explicitly told otherwise with the new clone
keyword.
但是，$ obj1 = $ obj2
和$ obj1 =& $ obj2是两回事...
第一个是按参考分配
第二个是按同义词分配
- --------------- assign1.php ---------------------
<？php
class Foo {
var $ name;
function Foo（$ i） {
$ this-> name ="我是$ i！\ n" ;;
}
}
$ a = new Foo（ha）;
$ b = $ a;
$ b = new Foo（ hee）;
echo" This is php"，phpversion（），" \ n\\\
";
print_r （$ a）;
print_r（$ b）;
？>
---- -------------输出
这是php 5.2.4
Foo对象
（
[姓名] =我是哈！
）
Foo对象
（
[姓名] =我是嘿！
）
--------- -------- assign2.php ---------------------
<？php
class Foo {
var $ name;
function Foo（$ i）{
$ this-> name ="我是$ i！\ n" ;;
}
}
$ a = new Foo（ha）;
$ b =& $ a;
$ b = new Foo（hee） ;
echo"这是php"，phpversion（），" \ n \ n";
print_r（$ a）;
print_r（$ b）;
？>
--------- --------输出
这是php 5.2.4
Foo对象
（
[名字] =我是嘻嘻！
）
Foo对象
（
[姓名] =我是嘿！
）
However, $obj1 = $obj2
and $obj1 = &$obj2 are two different things...
the first one is "assignment by reference"
the second one is "assignment by synonym"
----------------- assign1.php ---------------------
<?php
class Foo {
var $name;
function Foo($i) {
$this->name = "I''m $i!\n";
}
}
$a = new Foo("ha");
$b = $a;
$b = new Foo("hee");
echo "This is php ", phpversion(), "\n\n";
print_r($a);
print_r($b);
?>
----------------- output
This is php 5.2.4
Foo Object
(
[name] =I''m ha!
)
Foo Object
(
[name] =I''m hee!
)
----------------- assign2.php ---------------------
<?php
class Foo {
var $name;
function Foo($i) {
$this->name = "I''m $i!\n";
}
}
$a = new Foo("ha");
$b = &$a;
$b = new Foo("hee");
echo "This is php ", phpversion(), "\n\n";
print_r($a);
print_r($b);
?>
----------------- output
This is php 5.2.4
Foo Object
(
[name] =I''m hee!
)
Foo Object
(
[name] =I''m hee!
)
推荐答案
obj1 =
obj2与
不一样
obj1 =&
obj1 =&
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