PHP 객체지향의 회원입니다. PHP 객체지향에 대한 심층적인 지식이 있습니까?

<code><span><span><?php</span>header(<span>"content-type:text/html;charset=utf-8"</span>);

<span><span>class</span><span>C</span>{</span><span>const</span> PATH = <span>"C:/windows"</span>;<span>//类中不能使用 define定义常量</span><span>//静态属性</span><span>static</span><span>$count</span>  = <span>66</span>;<span>//等价于 static public $count = 66;</span><span>//实例属性</span><span>public</span><span>$name</span> = <span>"tom"</span>;<span>//等价于 var $name = "tom";</span><span>//默认的无参构造函数</span><span>//function __construct(){</span><span>//</span><span>//  echo "<br> __construct  无参构造方法被调用";</span><span>//}</span><span>//有参构造函数，一般用来类成员属性的初始化，php中一个类只能存在一个构造方法</span><span><span>function</span><span>__construct</span><span>(<span>$name</span>)</span>{</span><span>$this</span>->name = <span>$name</span>;
  <span>echo</span><span>"<br> __construct  有参构造方法被调用"</span>;
}

<span>//实例方法</span><span><span>function</span><span>instanceFun</span><span>()</span>{</span><span>echo</span><span>"<br>实例方法被调用"</span>;
  <span>echo</span><span>"<br>实例方法中访问常量:"</span>.<span>self</span>::PATH;
  <span>echo</span><span>"<br>实例方法中访问实例属性：{$this->name}"</span>;
  <span>echo</span><span>"<br>实例方法中访问静态属性："</span>.<span>self</span>::<span>$count</span>;<span>//self就代表类本身</span><span>//实例方法中调用静态方法</span><span>self</span>::staticFun();

}

<span>//静态方法</span><span>static</span><span><span>function</span><span>staticFun</span><span>()</span>{</span><span>echo</span><span>"<br>静态方法被调用"</span>;
  <span>echo</span><span>"<br>静态方法中访问常量:"</span>.<span>self</span>::PATH;
  <span>echo</span><span>"<br>静态方法中访问静态属性："</span>.<span>self</span>::<span>$count</span>;
  <span>//注意：静态方法中无法访问实例属性</span>}

<span>//析构方法，当对象被销毁的时候由系统去调用</span><span>//通常代码执行完，对象就会被销毁</span><span><span>function</span><span>__destruct</span><span>()</span>{</span><span>echo</span><span>"<br>对象 {$this->name} 被销毁"</span>;
}


}


<span>$object</span> = <span>new</span> C(<span>"哈利波特"</span>);
<span>$object</span>->instanceFun();
<span>echo</span><span>"<hr>"</span>;
C::staticFun();

<span>//下面代码会使$object指向的对象被销毁</span><span>//$object = null;</span><span>//$object = new C("秦始皇");;</span><span>//$object = 3;</span><span>//unset($object);</span><span>echo</span><span>"<br>程序最后一行代码。。。"</span>;</span></code>