新人学习PHP问题，发现书上代码不对

<meta http-equiv="Content-Type" content="text/html; charset=utf-8"><!--?php
class Person
{
private $name;
private $sex;
private $age;
function __construct($name="",$sex="男",$age=23)
{
$this--->name=$name;
$this->sex=$sex;
$this->age=$age;
}
function say()
{
echo "我的名字  ".$this->name."，性别  ".$this->sex."，年龄  ".$this->age."<br>";
}
function run()
{
echo $this->name."正在走路<br>";
}
}
class Student extends Person 
{
var $school;
function study()
{
echo $this->name."正在".$this->school."学习<br>";
}
}
class Teacher extends Student 
{
var $wage;
function teaching()
{
echo  $this->sex."正在".$this->school."教学，每个月工资为".$this->wage."<br>";
}
}
$teacher1=new Teacher("张三","男",40);
$teacher1->school="沈阳工学院";
$teacher1->wage=3000;
$teacher1->say();
$teacher1->run();
$teacher1->teaching();?>

回复讨论(解决方案)

是$this->sex获取不到数据。

额。。。。我马虎了，上面变量定义的是private属性，当然获取不到。。。

同样菜的鸟飞过.........

你没错，书上也没错！
只不过是错误检查的级别不同而已

error_reporting = E_ALL ^ E_NOTICE
就一致了

你没错，书上也没错！
只不过是错误检查的级别不同而已

error_reporting = E_ALL ^ E_NOTICE
就一致了 版主强大，耳目一新，不明觉厉，加油奋进！

private $name;
private $sex;
private $age;
private改成public