php面向对象编程之$this关键字

<?php
class Person{
            public $name;            
            public $age;            
            public $sex;            
            
        public function say(){    
               echo $this->name."说，"."他一边".$this->run()."一边".$this->eat("apple")."<br/>";
                           
        }       
                
        public function eat($name){     
            return "吃".$name;           
        }
        public function run(){      
            return "走路";           
        }       
    }
            
            
$Person1= new Person();
$Person2= new Person();
$Person1->name="张三";
$Person2->name="李四";
            
$Person1->say();
$Person2->say();
?>