PHP語法屬性

Question

的靜態屬性，我實現了一個單例模式類，以及誰可以在其他類這樣使用：

class myClass { 

private $attr; 

public function __construct() { 

    $this->attr = Singleton::getInstance; 

    echo $this->attr::$sngtAttr; // Throw an error 

     // witch syntax use whithout pass by a temp var ? 

    } 

} 

Answer 1

爲$ sngtAttr的靜態屬性？

如果不是，那麼只是：
echo $this->attr->sngtAttr; instead of echo $this->attr::$sngtAttr; 會做到這一點。

否則，因爲是靜態的：

echo Singleton::$sngtAttr;

Answer 2

你的問題是什麼呢？ 這是你如何做一個單身：

<?php 

class ASingletonClass 
{ 
    // Class unique instance. You can put it as a static class member if 
    // if you need to use it somewhere else than in yout getInstance 
    // method, and if not, you can just put it as a static variable in 
    // the getInstance method. 
    protected static $instance; 

    // Constructor has to be protected so child classes don't get a new 
    // default constructor which would automatically be public. 
    protected final function __construct() 
    { 
     // ... 
    } 

    public static function getInstance() 
    { 
     if(! isset(self::$instance)) { 
      self::$instance = new self; 
     } 

     return self::$instance; 
    } 

    // OR : 

    public static function getInstance() 
    { 
     static $instance; 

     if(! isset($instance)) { 
      $instance = new self; 
     } 

     return $instance; 

     // In that case you can delete the static member $instance. 
    } 

    public function __clone() 
    { 
     trigger_error('Cloning a singleton is not allowed.', E_USER_ERROR); 
    } 
} 

?> 

而且不要忘了（）當你調用的getInstance，這是一個方法，而不是一個成員。