解析错误：语法错误，意外“（”

Question

我有一个辅助类是这样的：

class Helper{ 

    public static $app_url = self::getServerUrl(); 
    /** 
    * Gets server url path 
    */ 
    public static function getServerUrl(){ 
     global $cfg; // get variable cfg as global variable from config.php Modified by Gentle 

     $port = $_SERVER['SERVER_PORT']; 
     $http = "http"; 

     if($port == "80"){ 
      $port = ""; 
     } 

     if(!empty($_SERVER["HTTPS"]) && $_SERVER["HTTPS"] == "on"){ 
      $http = "https"; 
     } 
     if(empty($port)){ 
      return $http."://".$_SERVER['SERVER_NAME']."/".$cfg['afn']; 
     }else{ 
      return $http."://".$_SERVER['SERVER_NAME'].":".$port."/".$cfg['afn']; 
     }   
    } 
} 

而且它给我：

Parse error: syntax error, unexpected '(' on the line with public static $app_url = self::getServerUrl();

Answer 1

你的问题是，你正试图定义因为你从来没有实例化类（静态），你正在调用一个静态变量，你不能调用一个自我静态函数。

如果我复制粘贴你的代码并运行它与PHP 7它给其他错误：

Fatal error: Constant expression contains invalid operations in C:\inetpub\wwwroot\test.php on line 4

解决您的问题，使用此：

<?php 
class Helper { 

    public static $app_url; 

    public static function Init() { 
     self::$app_url = self::getServerUrl(); 
    } 

    public static function getServerUrl(){ 

     global $cfg; // get variable cfg as global variable from config.php Modified by Gentle 

     $port = $_SERVER['SERVER_PORT']; 
     $http = "http"; 

     if($port == "80"){ 
      $port = ""; 
     } 

     if(!empty($_SERVER["HTTPS"]) && $_SERVER["HTTPS"] == "on"){ 
      $http = "https"; 
     } 
     if(empty($port)){ 
      return $http."://".$_SERVER['SERVER_NAME']."/".$cfg['afn']; 
     }else{ 
      return $http."://".$_SERVER['SERVER_NAME'].":".$port."/".$cfg['afn']; 
     } 

    } 

} 
Helper::Init();