通过$ var :: $ reference访问静态变量 [英] Access a static variable by $var::$reference

问题描述

我正在尝试通过使用变量类名来访问类中的静态变量.我知道，要访问该类中的 function ，您可以使用call_user_func():

I am trying to access a static variable within a class by using a variable class name. I'm aware that in order to access a function within the class, you use call_user_func():

class foo {
    function bar() { echo 'hi'; }
} 
$class = 'foo';
call_user_func(array($class, 'bar')); // prints hi

但是，当尝试访问该类中的静态变量时，此方法不起作用:

However, this does not work when trying to access a static variable within the class:

class foo {
    public static $bar = 'hi';
} 
$class = "foo";
call_user_func(array($class, 'bar')); // nothing
echo $foo::$bar; // invalid

如何获取此变量?可能吗?我有一种不好的感觉，即此功能仅在以后的PHP 5.3中可用，而我正在运行PHP 5.2.6.

How do I get at this variable? Is it even possible? I have a bad feeling this is only available in PHP 5.3 going forward and I'm running PHP 5.2.6.

推荐答案

您可以使用 reflection 做到这一点.给定类名，创建一个 ReflectionClass 对象，然后使用getStaticPropertyValue方法获取静态变量值.

You can use reflection to do this. Create a ReflectionClass object given the classname, and then use the getStaticPropertyValue method to get the static variable value.

class Demo
{
    public static $foo = 42;
}

$class = new ReflectionClass('Demo');
$value=$class->getStaticPropertyValue('foo');
var_dump($value);

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