一个理解PHP面向对象编程（OOP）的实例，面向对象编程oop

<?<span>php<br /><br />
    </span><span>class</span><span> Person{<br /><br />        //声明一个新变量公共变量<strong>$name</strong>，可被任何包中的类访问<br />        </span><span>public</span> <span>$name</span><span>;
        </span><span>public</span> <span>$sex</span><span>;
        </span><span>public</span> <span>$age</span><span>;<br /><br />        //声明该类的一个方法
        </span><span>function</span><span> say() {
            </span><span>echo</span> "你好！<br />"<span>;
            </span><span>echo</span> "我的的名字是：" . <span>$this</span> -> name ."<br />"<span>;
            </span><span>echo</span> "我的性别是：" . <span>$this</span> -> sex ."<br />"<span>;
        }
    }
<br />    //声明新的Student类为Person的子类
    </span><span>class</span> Student <span>extends</span><span> Person{
        </span><span>public</span> <span>$school</span><span>;
        </span><span>function</span><span> study() {<br />            //parent:: 可用于调用父类中定义的成员方法。<br />            parent::say();</span><span>echo</span> "我的年龄是：" . <span>$this</span> -> age . "<br />我正在" . <span>$this</span> -> school . "上学。"<span>;
        }
    }
<br />　　//只用将P1定义为学生类即可
    </span><span>$p1</span> = <span>new</span><span> Student();<br /><br />    //为P1的name，sex，age，school属性赋值
    </span><span>$p1</span> -> name = "张三"<span>;
    </span><span>$p1</span> -> sex = "男"<span>;
    </span><span>$p1</span> -> age = "18"<span>;
    </span><span>$p1</span> -> school = "某某学校"<span>;
    </span><span>$p1</span> -><span> study();
</span>?>