PHP 命名空间和“使用" [英] PHP namespaces and "use"

问题描述

我在命名空间和 use 语句方面遇到了一点问题.

I am having a little trouble with namespaces and the use statements.

我有三个文件:ShapeInterface.php、Shape.php 和 Circle.php.

I have three files: ShapeInterface.php, Shape.php and Circle.php.

我正在尝试使用相对路径来执行此操作，因此我已将其放入所有类中:

I am trying to do this using relative paths so I have put this in all of the classes:

namespace Shape; 

在我的圈子课程中，我有以下内容:

In my circle class I have the following:

namespace Shape;
//use Shape;
//use ShapeInterface;

include 'Shape.php';
include 'ShapeInterface.php';    

class Circle extends Shape implements ShapeInterface{ ....

如果我使用 include 语句，我不会出错.如果我尝试 use 语句，我会得到:

If I use the include statements I get no errors. If I try the use statements I get:

致命错误:在中找不到类ShapeShape"/Users/shawn/Documents/work/sites/workspace/shape/Circle.php 在第 8 行

Fatal error: Class 'ShapeShape' not found in /Users/shawn/Documents/work/sites/workspace/shape/Circle.php on line 8

有人可以就这个问题给我一些指导吗?

Could someone please give me a little guidance on the issue?

推荐答案

use operator 用于为类、接口或其他命名空间的名称提供别名.大多数 use 语句引用您想要缩短的命名空间或类:

The use operator is for giving aliases to names of classes, interfaces or other namespaces. Most use statements refer to a namespace or class that you'd like to shorten:

use MyFullNamespace;

相当于:

use MyFullNamespace as Namespace;
// NamespaceFoo is now shorthand for MyFullNamespaceFoo

如果 use 操作符与类或接口名称一起使用，它有以下用途:

If the use operator is used with a class or interface name, it has the following uses:

// after this, "new DifferentName();" would instantiate a MyFullClassname
use MyFullClassname as DifferentName;

// global class - making "new ArrayObject()" and "new ArrayObject()" equivalent
use ArrayObject;

use 运算符不要与 autoloading 混淆.通过注册一个自动加载器(例如使用 spl_autoload_register)来自动加载一个类(不需要 include).您可能想阅读 PSR-4 以了解合适的自动加载器实现.

The use operator is not to be confused with autoloading. A class is autoloaded (negating the need for include) by registering an autoloader (e.g. with spl_autoload_register). You might want to read PSR-4 to see a suitable autoloader implementation.

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