PHP-类外的use关键字与类内的use关键字的区别 [英] PHP - difference of use keyword outside of class and use keyword inside of a class

问题描述

大家好！

只想问一下class内class和 use 的区别?我也用谷歌搜索，但是我的问题与答案不符.

Just want to ask the difference of use outise the class and use inside the class ? I have also googled it, but my question doesnt match an answer.

示例:

namespace App\Http\Controllers\Auth;

use Validator;
use App\Http\Controllers\Controller;
use Illuminate\Foundation\Auth\ThrottlesLogins;
use Illuminate\Foundation\Auth\AuthenticatesAndRegistersUsers;
use Auth;
use Illuminate\Http\Request;

class AuthController extends Controller
{

    use AuthenticatesAndRegistersUsers, ThrottlesLogins;

    protected $redirectTo = '/';

    /**
     * Create a new authentication controller instance.
     *
     * @return void
     */
    public function __construct()
    {
       // Some Code
    }

推荐答案

定义类时，它只能访问其命名空间中的其他类.例如，您的控制器在以下名称空间中定义.

When you define a class, it can only have access to other classes within its namespaces. Your controller for instance is defined within the following namespace.

namespace App\Http\Controllers\Auth;

因此，要使用其他类，您需要从它们自己的名称空间中导入它们，以便可以访问它们.例如:

So to use other classes, you need to import them from their own namespaces so you can access them. e.g.:

use Illuminate\Foundation\Auth\ThrottlesLogins;

如果您具有JavaScript ES6经验，则与import有点相似.导入软件包时，默认名称空间为/node_modules.要导入自己的文件，您需要通过给文件位置类似

If you have javascript ES6 experience, it's a little bit similar to import. When you import a package, the default namespace is /node_modules. To import your own files, you need to sort of namespace them by giving the file location like

import '../containers/index.js'

回到Laravel.现在，您已经导入了ThrottlesLogins(实际上是一个特征)，现在将其放入类中，以显示所有内部方法.

Back to Laravel. Now that you have imported the ThrottlesLogins, which is actually a trait, now inside the class you use it to expose all of the methods inside.

use Illuminate\Foundation\Auth\ThrottlesLogins; //import
public class AuthController
{
    use ThrottlesLogins; //exposes all the methods inside
    ...

    public function login()
    {
        ...
        //login failed 
        $this->incrementLoginAttempts(); //defined in ThrottlesLogins Trait
    }
}

在上面的示例中，您可以直接访问定义为ThrottlesLogins的incrementLoginAttempts().

From the example above, you have direct access to incrementLoginAttempts(), which is defined the ThrottlesLogins.

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