<?php  class Cat{  //public 访问修饰符   public $name;   public $age;  }  //创建  $cat1=new Cat;  $cat1->name="小白";  //访问某个对象的某个属性 $对象名->属性名  echo $cat1->name;  echo "<br/>";  class Person  {     public $name;     public $age;  }    $a=new Person();  $a->name="小明";  $a->age=20;  //  $b=$a;  echo $a->name."<br/>";  echo $b->name."<br/>";    echo "<br/>";  $p1=new Person();  $p1->name="张三";  $p1->age=7;  function test1($p)  {     $p->name="王五";  }  echo $p1->name; //输出张三。证明说传的是值而不是地址传递?>