PHP类与继承

<?php
  class Person
  {
  	private $name;
  	private $age;

  	function __construct($name,$age){
  		$this->name = $name;
  		$this->age = $age;
  	}

  	public function setName($name)
  	{
  		$this->name = $name;
  	}

  	public function getName()
  	{
  		return $this->name;
  	}

  	public function setAge($age)
  	{
  		$this->age = $age;
  	}

  	public function getAge()
  	{
  		return $this->age;
  	}

  	public function SayHello()
  	{
  		printf("<br/>name:%s,age:%d",$this->name,$this->age);
  	}
  }

  $person = new Person("zhangsan", 20);
  $person->SayHello();

  class Student extends  Person
  {
  	private $work;
  	function __construct($name,$age,$work)
  	{
  		parent::__construct($name, $age);
  		$this->work = $work;
  	}

  	public function setWork($work)
  	{
  		$this->work = "学生";
  	}

  	public function getWork()
  	{
  		return $this->work;
  	}

  	public function Introduce()
  	{
  		printf("<br/>name:%s,age:%d,work:%s",$this->getName(),$this->getAge(),$this->getWork());
  	}
  }

  $student = new Student("wangwu", 18, "学生");
  $student->SayHello();
  $student->Introduce();
?>