在PHP中使用array [key]可以吗? [英] Is it okay to use array[key] in PHP?

问题描述

可以使用不带单引号或双引号的数组，例如$ array [key]吗?我认为这很糟糕，因为如果我不使用单引号或双引号，PHP首先会寻找常量.我的一位同事告诉我，没关系.

Is it okay to use array without single or double quotion like $array[key]? I thought it is bad because PHP look for constant first if I don't use single or double quotation. One of my colleagues told me that it does not matter.

你们怎么看?

推荐答案

即使在大多数情况下都可以正常使用，它也不被认为是正确的.

基本上，当PHP看到此信息时:

Basically, when PHP sees this :

echo $array[key];

它将搜索用 define 定义的常量，称为 key ；如果没有，则采用'key'值.

It will search for a constant, defined with define, called key -- and, if there is none, if will take the 'key' value.

但是，如果您的代码前面有这样的内容:

But, if there is something like this earlier in your code :

define('key', 'glop');

不需要

echo $array['key'];

了；相反，它将使用 key常量的值-您的代码将与:

anymore ; instead, it'll use the value of the key constant -- and your code will be the same as :

echo $array['glop'];

最后，至少有两个原因，不把引号引起来是不好的:

In the end, not putting quotes arround the key's name is bad for at least two reasons :

• 它可能无法达到您的期望，这很危险-这是非常糟糕的
  • 今天可能会...
  • 但是下周/月/年呢?
  • 也许有一天，您会define一个名称为错误的常量;-)
  • There is a risk that it will not do what you expect -- which is very bad
    • It might, today...
    • But what about next week / month / year ?
    • Maybe, one day, you'll define a constant with the wrong name ;-)
    • 在使用'key'
    之前，它必须搜索一个常量.
    • 而且，如评论中所述，它会生成通知(即使您禁用 display_errors ，即使以后将其丢弃，仍然会生成通知/警告/错误)
    • it has to search for a constant, before using 'key'
    • And, as said in a comment, it generates notices (even if you disable error_reporting and display_errors, the notices/warnings/errors are still generated, even if discarded later)

    所以:在这一点上，您不应该听那个家伙的话:他错了:这很重要.

    So : you should not listen to that guy on this point : he is wrong : it does matter.

    
    并且，如果您需要某种证明"，而证明"比人们在堆栈溢出方面所能告诉您的要好，则可以将他指向手册的本部分，作为参考:

    
    And if you need some "proof" that's "better" than what people can tell you on stackoverflow, you can point him to this section of the manual, as a reference : Why is $foo[bar] wrong?

    这篇关于在PHP中使用array [key]可以吗?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！