奇怪的语法错误

Question

我得到这个错误：

Parse error: syntax error, unexpected '.', expecting ',' or ';' in /var/(...)/config.php on line 5

有了这个（简化）代码：

<?php 

class Config 
{ 
    public static $somevar = "Date: " . date('Y'); 
} 

?> 

我认为这是有效的PHP，但我想不会...我在这里做错了什么？谢谢！

Answer 1

根据the PHP docs：

Like any other PHP static variable, static properties may only be initialized using a literal or constant; expressions are not allowed. So while you may initialize a static property to an integer or array (for instance), you may not initialize it to another variable, to a function return value, or to an object.

尝试类定义后写

Config::$somevar = "Date: " . date('Y'); 

。

Answer 2

从Manual

Like any other PHP static variable, static properties may only be initialized using a literal or constant; expressions are not allowed. So while you may initialize a static property to an integer or array (for instance), you may not initialize it to another variable, to a function return value, or to an object.

Answer 3

无操作或功能是允许属性初始化，因为在解析时，这是评估。