这是如何为php编写Singleton类的？ [重复]

Question

This question already has an answer here:

• Creating the Singleton design pattern in PHP5 20 answers

Is this the right way if I want properly write a Singleton class so that a maximum of one SingleClass object exists.

<?php
class SingleClass
{
    static $object;

    static public function getSingleton()
    {
        if(!isset(self::$object))
        {
            self::$object = new SingleClass();
        }
        return self::$object;
    }

    private function __construct()
    {

    }

}
$mySingle1 = SingleClass::getSingleton();   // one object made
$mySingle2 = SingleClass::getSingleton();   // reference to first object returned
$mySingle3 = SingleClass::getSingleton();   // reference to first object returned
?>

if this is how it's done how can I do a check on it with if/else functions?

</div>

Answer 1

Yes this is a singleton in php. My only edit would be to restrict the clone operation. This can be done by throwing an exception within the __clone magic method