public $name; public $sex; public $iq=10; const BIRTHPLACE='地球'; static public $counter=0;//静态属性，它是公共的资源和具体的实例没有关系 //构造函数 public function __construct($name,$sex){ self::$counter++; $this->name=$name; $this->sex=$sex; } protected function chew($food){ echo "
{$food}已经被咀嚼完成！
"; } public function eat($food){ $this->chew($food); echo "
{$this->name}正在吃{$food}！
"; } static public function hello(){ echo '
您好！我是来自'.self::BIRTHPLACE.'的人类
'; } } class Student extends Humanity { const BIRTHPLACE='火星'; public $studentId; public function test($subject){ echo "
{$this->name}正在考{$subject}！
"; } public function eat($food){ $this->chew($food); echo "
{$this->name}正在快速的吃{$food}！
"; } } new Humanity('',''); new Humanity('',''); new Humanity('',''); new Humanity('',''); new Humanity('',''); new Humanity('',''); echo Humanity::$counter; Humanity::hello();
解析：
注意：静态成员里面不能使用$this不然会报错
问题：子类怎么访问父类的方法变量常量：
parent::
怎么在类内部访问自己的方法变量常量：
self::
