<?php/** * Created by PhpStorm. * User: Administrator * Date: 2015/8/30 * Time: 12:53 */class Singleton{ private static $instance = null; private function __construct($name){ $this->name = $name; } public static function getInstance(){ if(self::$instance==null){ return new Singleton(""); } return self::$instance; } public function printString(){ echo "hello,this is printString()"."<br/>"; } public function setName($name){ $this->name = $name; } public function getName(){ echo "The name is ".$this->name."<br/>"; }}$class = Singleton::getInstance();$class->printString();$class->setName("jack");$class->getName();$class2 = Singleton::getInstance();$class2->getName();
return new Singleton(""):
应为
self::$instance = new Singleton(""):
如果 return new Singleton(""): 的话就直接返回了另一个实例
就不是单例模式了
<?php/** * Created by PhpStorm. * User: Administrator * Date: 2015/8/30 * Time: 12:53 */class Singleton{ private static $instance = null; private function __construct($name){ $this->name = $name; } public static function getInstance(){ if(self::$instance==null){ return new Singleton(""); } return self::$instance; } public function printString(){ echo "hello,this is printString()"."<br/>"; } public function setName($name){ $this->name = $name; } public function getName(){ echo "The name is ".$this->name."<br/>"; }}$class = Singleton::getInstance();$class->printString();$class->setName("jack");$class->getName();$class2 = Singleton::getInstance();$class2->getName(); 只要改一处代码即可：你忘了把单例放入$instance
public static function getInstance(){ if(self::$instance==null){ self::$instance= new Singleton(""); } return self::$instance; }
