PHP实现一个限制实例化次数的类示例

本文实例讲述了php实现一个限制实例化次数的类。分享给大家供大家参考，具体如下：

实现思平凡的世界片尾曲路

定义一个static变量$count，用于保存实例化对象的个数定义一个static方法create，通过该方法判断$count的值，进而判断是否进一步实例化对象。定义构造函数，$count+1定义析构函数，$count-1

实现代码

<?phpclass demo{  public $name;  public static $count=0;  private functiont8620 __construct($name){    echo "create $name <br/>";    $this->name = $name;    lf::$count++;  }  public function __destruct(){    echo "destory ".$this->name."<br/>";    lf::$count--;  }  public static function create($name){    if(lf::$count>2){      di追寻红色足迹e("you can only create at most 2 objects.");    }el{      return new lf($name);    }  }}$one = demo::create("one");$two = demo::create("two");$two = null;$three = dem北京美食攻略o::create("three");

运行结果：

create one
create two
destory two
c深化改革reate three
destory three
destory one