php中构造函数对变量的引用怎么没有值啊？

[potency]

本人初学php，下面的程序输出结果，$name都为空。各位知道咋回事吗？
<?php
class base
{
private $name ;

function __construct ($name2)
{
$name=$name2;
echo "base(__construct):my name:".$name ."\n";
}

function __destruct ()
{
echo "base(__destruct):"."\n";
}
}

class TestClass extends base
{
private $name ="Son";
function __construct ()
{
parent::__construct($name);
echo "TestClass(__construct):my name:".$name."\n";
}

function __destruct ()
{
echo "TestClass(__destruct):"."\n";
}
}

$testClass=new TestClass();

?>

[potency]

有人帮忙看看吗？

[potency]

为什么要用$this来引用自己的成员变量呢

[potency]

还是不行，说$this->$name 未定义!!!
----------------------------------------
X-Powered-By: PHP/5.2.9 ZendServer/4.0
Set-Cookie: ZendDebuggerCookie=127.0.0.1%3A10137%3A0||084|77742D65|1006; path=/
Content-type: text/html

<br />
<b>Fatal error</b>: Cannot access empty property in <b>G:\DedeAMPZ\WebRoot\Default\work\phpTest\TestClass.php</b> on line <b>22</b><br />

[potency]

人呢???????????

[xuzuning]

class TestClass extends base
{
private $name ="Son";
function __construct ()
{
parent::__construct($this->name);
echo "TestClass(__construct):my name:".$this->name."\n";
}

function __destruct ()
{
echo "TestClass(__destruct):"."\n";
}
}

[木目子]

试试这个
class TestClass extends base
{
private $name ="Son";
function __construct ()
{
parent::__construct($this->name);
echo "TestClass(__construct):my name:".$this->name."\n";
}

function __destruct ()
{
echo "TestClass(__destruct):"."\n";
}
}

[木目子]

多打四个字，比老大慢了12秒……

[heyli]

$this->name
找本基础的书看看