PHP OOP扩展外部类

Question

Im new to OOP in PHP. I just can't extend a class from an external file. They are both on the same folder.

DB.php

<?php

class DB {
   // some functions here
}

Home.php

<?php
require_once("DB.php");
class Home extends DB {
   // initialize db and some functions here
}

and I get an error: Fatal error : Class 'DB' not found in \\location\\to\\Home.php on line 3

Answer 1

It should be an absolute path import

require_once __DIR__ . '/DB.php';

Why: because otherwise the relative import is evaluated relatively to your current working directory, which is basically can be anything during the runtime. So it's recommended to always require files with the absolute path.