class User{
public $company_name;
}
class Employer extends User{
public $fname;
public $sname;
}
$employer = new Employer(); $user = new User(); $employer->company_name = "Company name is "; echo $user->company_name;
您的Employer类扩展了您的User类,但是当您创建$user和$employer对象时,它们是独立的实体且不相关.
原文链接：https://www.f2er.com/php/136752.html想想你的对象：
$employer = new Employer(); // You now have $employer object with the following properties: // $employer->company_name; // $employer->fname; // $employer->sname; $user = new User(); // You now have $user object with the following properties: // $user->company_name; $employer->company_name = "Company name is "; // You now have $employer object with the following properties: // $employer->company_name = 'Company name is '; // $employer->fname; // $employer->sname; echo $user->company_name; // You currently have $user object with the following properties: // $user->company_name; /* no value to echo! */
如果要使用继承的属性,它的工作方式更像：
class User{
public $company_name;
function PrintCompanyName(){
echo 'My company name is ' . $this->company_name;
}
}
class Employer extends User{
public $fname;
public $sname;
}
$employer = new Employer();
$employer->company_name = 'Rasta Pasta';
$employer->PrintCompanyName(); //echoes 'My company name is Rasta Pasta.'
