<?phpclass classname{  var $attr1;  var $attr2;  public $attribute;  const PI = 3.14;  // 構(gòu)造函數(shù)  function __construct($param = 'default'){    echo "Constructor called with parameter $param<br />";  }  // 析構(gòu)函數(shù)  function __destruct(){    echo '<br />destruct';  }  //  function oper1(){    echo 'oper1<br />';  }  function oper2($param){    $this->attr1 = $param;    echo $this->attr1;  }  protected function oper3(){    echo 'this is protected function<br />';  }  // 禁止繼承  final function oper5(){  }  function __get($name){    return $this->$name;  }  function __set($name, $value){    $this->$name = $value;  }  // 靜態(tài)方法  static function double($param){    return $param * $param;  }}$a = new classname('First');$b = new classname('Second');$c = new classname();$c->oper2("hello");echo '<br />';echo $c->attr1;echo '<br /><br />';echo ' Per-Class常量 classname::PI -'.classname::PI;echo '<br />靜態(tài)方法: classname::double(3) - ' . classname::double(3);echo '<br />';// 實(shí)現(xiàn)繼承echo '實(shí)現(xiàn)繼承<br />';class B extends classname{  function oper4(){    $this->oper3(); // protected方法只能在  }  function oper1(){ // 重載    echo 'this is class B /'s oper1. <br />';  }}$d = new B("forth");$d->oper1();$d->oper4();// 接口interface Displayable{  function display();  function show();}class C implements Displayable{  function display(){    echo '這是對應(yīng)接口的方法.<br />';  }  function show(){}}$e = new C();$e->display();echo '檢查$e是否為C的實(shí)例:';echo ($e instanceof C) ? 'Yes':'No';// 克隆對象$f = clone $e;echo '<br /><br />可以使用__clone()方法，在使用clone關(guān)鍵字時(shí)調(diào)用';// 抽象類abstract class E{}// $f = new E(); // 這行將報(bào)錯(cuò),不能實(shí)例化抽象類//　參數(shù)重載，多態(tài)class F{  public $a = 1;  public $b = 2;  public $c = 3;  function displayString($elem){    echo '<br />string:'.$elem;  }  function displayInt($elem){    echo '<br />int:'.$elem;  }  // 注意參數(shù)$p，是作為數(shù)組傳入，必須使用下標(biāo)訪問  function __call($method, $p){    if ($method == 'display'){      if (is_string($p[0])){        $this->displayString($p[0]);      } else {        $this->displayInt($p[0]);      }    }  }}$g = new F();$g->display('abc');// 迭代器,讀出實(shí)例的所有屬性foreach ($g as $att){  echo '<br />'.$att;}// 反射echo '<br />';$class = new ReflectionClass('F');echo '<pre>';echo $class;echo '</pre>';?>