更改Man.php文件名为People.php，加入代码：
<span>1</span> <span>public</span> <span>function</span><span> hi(){
</span><span>2</span> <span>return</span> <span>$this</span>->_name.' say hi'<span>;
</span><span>3</span> }新建文件Man.php：
<span> 1</span> <?<span>php
</span><span> 2</span> <span>/*</span><span>*
</span><span> 3</span> <span> * Created by PhpStorm.
</span><span> 4</span> <span> * User: Administrator
</span><span> 5</span> <span> * Date: 2015/6/29
</span><span> 6</span> <span> * Time: 11:18
</span><span> 7</span> <span>*/</span>
<span> 8</span>
<span> 9</span> <span>require_once</span> 'People.php'<span>;
</span><span>10</span>
<span>11</span> <span>class</span> Man <span>extends</span> People{<span>//</span><span>extends:继承People类</span>
<span>12</span> <span>public</span> <span>function</span> __construct(<span>$age</span>,<span>$name</span><span>){
</span><span>13</span> parent::__construct(<span>$age</span>,<span>$name</span>,'男'<span>);
</span><span>14</span> <span> }
</span><span>15</span>
<span>16</span> <span>public</span> <span>function</span> hi(){<span>//</span><span>重写People类的hi方法
</span><span>17</span> <span>// echo parent::hi();//保留父类hi方法</span>
<span>18</span> <span>echo</span> 'Man '.<span>$this</span>->getName().' say hi'<span>;
</span><span>19</span> <span> }
</span><span>20</span> }如果保留父类方法，可以这么写parent::hi();这里不保留，添加下面一行
修改index.php文件：
<span>1</span> <span>require_once</span> 'Man.php'<span>; </span><span>2</span> <span>$m</span> = <span>new</span> Man(10,'Vito'<span>); </span><span>3</span> <span>echo</span> <span>$m</span>->hi();
最后在网页上可以看到成功输出的信息：Man Vito say hi
