php 中使用cache做计数器

计数器在程序中很常见，下面我们使用cahce 来作为一个计数器

<?phpclass Counter{ private $counter ; private $oMemcache ;  public function __construct ($key) {            $this->$counter = $key ;      }  /***/    public function incr(){$num = $this->oMemcache->get($this->$counter);$this->oMemcache->set($this->$counter, $num+1);return $num +1; }    public function set(){return $this->oMemcache->set($this->$counter, $num+1);}public function get(){return $this->oMemcache->get($this->$counter);} /**     连接memcache 服务器      */      public  function connect() {          if (! isset ( $this->oMemcache )) {              $this->oMemcache = new Memcache ();              $this->oMemcache->connect ( '127.0.0.1', 11211 );          }          return $this->oMemcache;      }  }$oCounter = new Counter('11');?>