如何使用名称空间并在PHP中使用？

Question

我在Main目录中有文件index.php;

还有目录Helpers里面Main与类Helper。

我试图在index.php注入Helpers\Helper类为：

<? 

namespace Program; 

use Helpers\Helper; 


class Index { 

    public function __construct() 
    { 
     $class = new Helper(); 
    } 

} 

但它不工作。

如何使用命名空间和在PHP中使用？

Answer 1

With Your Description, Your Directory Structure should look something similar to this:

Main* 
     -- Index.php 
     | 
     Helpers* 
       --Helper.php 

If You are going by the book with regards to PSR-4 Standards, Your Class definitions could look similar to the ones shown below:

的index.php

<?php 
     // FILE-NAME: Index.php. 
     // LOCATED INSIDE THE "Main" DIRECTORY 
     // WHICH IS PRESUMED TO BE AT THE ROOT OF YOUR APP. DIRECTORY 

     namespace Main;   //<== NOTICE Main HERE AS THE NAMESPACE... 

     use Main\Helpers\Helper; //<== IMPORT THE Helper CLASS FOR USE HERE 

     // IF YOU ARE NOT USING ANY AUTO-LOADING MECHANISM, YOU MAY HAVE TO 
     // MANUALLY IMPORT THE "Helper" CLASS USING EITHER include OR require 
     require_once __DIR__ . "/helpers/Helper.php"; 

     class Index { 

      public function __construct(){ 
       $class = new Helper(); 
      } 

     } 

Helper.php

<?php 
     // FILE NAME Helper.php. 
     // LOCATED INSIDE THE "Main/Helpers" DIRECTORY 


     namespace Main\Helpers;  //<== NOTICE Main\Helpers HERE AS THE NAMESPACE... 


     class Helper { 

      public function __construct(){ 
       // SOME INITIALISATION CODE 
      } 

     }