为什么在使用命名空间时必须包含PHP文件？

Question

假设我已经声明了这样的命名空间:

<?php
// File kitchen.php
namespace Kitchen;
?>

为什么我仍然必须在我想使用kitchen.php的所有其他文件中包含该文件
PHP不知道kitchen.php驻留在Kitchen命名空间中吗？

谢谢你的回答.

Answer 1

命名空间使您可以非常轻松地为项目中的任何类创建自动加载器,因为您可以直接在调用中包含类的路径.

伪代码名称空间示例.

<?php 
// Simple auto loader translate \rooms\classname() to ./rooms/classname.php
spl_autoload_register(function($class) {
    $class = str_replace('\\', '/', $class);
    require_once('./' . $class . '.php');
});

// An example class that will load a new room class
class rooms {
    function report()
    {
        echo '<pre>' . print_r($this, true) . '</pre>';
    }

    function add_room($type)
    {
        $class = "\\rooms\\" . $type;
        $this->{$type}  = new $class();
    }
}

$rooms = new rooms();
//Add some rooms/classes
$rooms->add_room('bedroom');
$rooms->add_room('bathroom');
$rooms->add_room('kitchen');

然后在./rooms/文件夹中有3个文件: bedroom.php bathroom.php kitchen.php

<?php 
namespace rooms;

class kitchen {
    function __construct()
    {
        $this->type = 'Kitchen';
    }
    //Do something
}
?>

然后报告类加载的类

<?php
$rooms->report();
/*
rooms Object
(
    [bedroom] => rooms\bedroom Object
        (
            [type] => Bedroom
        )

    [bathroom] => rooms\bathroom Object
        (
            [type] => Bathroom
        )

    [kitchen] => rooms\kitchen Object
        (
            [type] => Kitchen
        )

)
*/
?>

希望能帮助到你