PHP 将值返回到新数组时出错

Question

我想使用另一个 class 的静态方法返回的值构建一个新数组，如下所示：

class Foo {
    public static $vars = array(
        'foo' => Config::method('returns a string'), /* line where error occurs */
        'bar' => Config::anothermethod('another string')
    );
}

现在 PHP 抛出此错误：

Parse error: syntax error, unexpected '(', expecting ')' in file.php on line 22

该方法只是 returns 一个字符串，我仔细检查过。我什至尝试用 (string) Config::method('foo') 对其进行字符串化，但没有成功。这不可能吗？

Answer 1

class 变量的声明必须是常量表达式。方法调用不是常量表达式。

http://php.net/manual/en/language.oop5.properties.php

This declaration may include an initialization, but this initialization must be a constant value--that is, it must be able to be evaluated at compile time and must not depend on run-time information in order to be evaluated.

PHP 将值返回到新数组时出错

PHP Error when returning value into new array

php

arrays

oop

syntax