單例模式：達到只有一個例項

程式碼如下：

<?php
class C{
    private static $_instance;
    private function __construct(){
        
    }
    public static function getInstance(){
        if(!(self::$_instance instanceof self)){
            self::$_instance = new self;
        }
        return self::$_instance;
    }
}
$o = C::getInstance();
?>
 

工廠模式：專門用於生產物件

程式碼如下：

<?php 
class C {
}

class Factory {
    private static $instances;//儲存所有的例項
    public static function getInstance($class_name) {
        $class_name = strtolower($class_name);//將所有的都轉換成小寫
        if(!isset(self::$instances[$class_name])) {
            self::$instances[$class_name] = new $class_name;
        }

        return self::$instances[$class_name];
    }
}
$c1 = Factory::getInstance('C');

?>