PHP 戏法常量

<?php  /** 在你的公用的配置文件中，来设置你的根目录，这样就不用担心经常搬家了。 */  define('ROOT_PATH', dirname(__FILE__) . DIRECTORY_SEPARATOR);  echo ROOT_PATH;  echo "<br>";  echo __FILE__;  echo "<br>";  echo dirname(__FILE__);  echo "<br>";  echo dirname(dirname(__FILE__));  ?>  

<?php  echo __LINE__;  //显示，__LINE__所在的行号  ?> 

<?php  class base_class  {   function say_a()   {   echo "'a' - said the " . __CLASS__ . "<br/>";   }   function say_b()   {   echo "'b' - said the " . get_class($this) . "<br/>";   }  }    class derived_class extends base_class  {   function say_a()   {   parent::say_a();   echo "'a' - said the " . __CLASS__ . "<br/>";   }   function say_b()   {   parent::say_b();   echo "'b' - said the " . get_class($this) . "<br/>";   }  }    $obj_b = new derived_class();  $obj_b->say_a();  echo "<br/>";  $obj_b->say_b();  ?>  结果为：  'a' - said the base_class  'a' - said the derived_class    'b' - said the  derived_class  'b' - said the derived_class  

<?php  class test  {   function a()   {   echo __FUNCTION__;   echo "<br>";   echo __METHOD__;   }  }    function good (){   echo __FUNCTION__;   echo "<br>";   echo __METHOD__;  }    $test = new test();  $test->a();  echo "<br>";  good();  ?>  返回结果：  a  test::a  good  good 

<?php  if(!defined('__DIR__')) {   $iPos = strrpos(__FILE__, "/");   define("__DIR__", substr(__FILE__, 0, $iPos) . "/");  }  ?> 

<?php  //php5.3  class Model  {   public static function find()   {   echo __STATIC__;   }  }    class Product extends Model {}  class User extends Model {}    Product::find(); // "Product"  User::find(); // "User"  ?>