PHP 中的裸字符串是否有任何合法用途? [英] Is there any legitimate use for bare strings in PHP?

问题描述

这个问题让我想到了裸字符串.

当 PHP 看到一个没有用引号括起来的字符串时，它首先检查它是否是一个常量.如果不是，它只是假设它是一个字符串，然后继续.例如，如果我有

When PHP sees a string that's not enclosed in quotes, it first checks to see if it's a constant. If not, it just assumes it's a string and goes on anyway. So for example if I have

echo $foo[bar];

如果有一个名为 bar 的常量，它会将它用作数组键，但如果没有，则它将 bar 视为一个裸字符串，因此它的行为就像

If there's a constant called bar it uses that for the array key, but if not then it treats bar as a bare string, so it behaves just like

echo $foo["bar"];

如果在未来某个日期添加同名常量，这可能会导致各种问题.

This can cause all kinds of problems if at some future date a constant is added with the same name.

我的问题是，在任何情况下使用裸字符串是否真的有意义?

My question is, is there any situation in which it actually makes sense to use a bare string?

推荐答案

不，我看不到一个有意义的实例，而且它总是很危险.绝对应该保留使用不带引号的字符串来处理常量.我完全不明白 PHP 的发明者是如何决定引入这种荒谬的行为的——这使得正确使用常量几乎是不可能的(因为如果你试图访问一个尚未定义的常量，PHP 会默默地、愚蠢地生成一个字符串)而不给任何好处.

Nope, I can not see a single instance where it would make sense, and it always is dangerous. Using strings without quotes should absolutely be reserved to address constants. I don't understand how the inventors of PHP could decide to introduce this ridiculous behaviour at all - it makes the proper use of constants almost impossible (because if you try to access a constant that has not been defined, PHP will silently and stupidly generate a string) without giving any benefit.

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