Inheritance and extension operation skills of php class

This article mainly introduces the inheritance and extension operation skills of PHP classes. Interested friends can refer to it. I hope it will be helpful to everyone.

The examples in this article describe the extension and inheritance usage of PHP classes, as follows:

<?php 
class Thread 
{ 
  var $topic; //帖子主题 
  var $body; //帖子内容 
  var $date; //帖子发布时间 
  var $author; //帖子作者 
  //函数Thread用于初始化变量等 
  function Thread() 
  { 
    //初始化变量 
  } 
  //函数Send用于提交新帖子 
  function Send() 
  { 
    //检测变量的合法性后执行插入操作将变量存储到数据库中 
  } 
  //函数Edit用于编辑帖子 
  function Edit() 
  { 
    //检测变量的合法性后执行更新操作将变量存储到数据库中 
  } 
  //函数Delete用于删除帖子 
  function Delete() 
  { 
    //检测作者的权限后将从数据库中将相关数据删除 
  } 
} 
class MainThread extends Thread 
{ 
  var $id; //帖子编号 
  var $board; //帖子所在讨论区 
  var $allowreply; //是否允许回复 
  //构造函数，用于初始化变量 
  function MainThread($id, $board, $allowreply) 
  { 
    //用于初始化变量 
  } 
  function Send() 
  { 
    //检测变量的合法性后执行插入操作将变量存储到数据库中 
    parent::Send(); //用于调用基类的Send函数 
  } 
  function Edit() 
  { 
    //检测变量的合法性后执行更新操作将变量存储到数据库中 
    parent::Edit(); //用于调用基类的Edit函数 
  } 
} 
$th = new Thread; //创建新对象 
if ($th instanceof Thread) //如果对象$th是Thread类型的，则输出Yes 
  echo "Yes"; 
else 
  echo "No"; 
?>

Summary: The above is the entire content of this article, I hope it can be helpful to everyone Learning helps.

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