在jQuery源码中理解空格正则表达式

Question

我只是想了解jQuery的源代码的空白修剪REGEX和遇到以下:

rtrim = /^[suFEFFxA0]+|[suFEFFxA0]+$/g,

现在使用REGEX工具，我理解了以下内容:

/^[suFEFFxA0]+|[suFEFFxA0]+$/g
1st Alternative: ^[suFEFFxA0]+
^ assert position at start of the string
[suFEFFxA0]+ match a single character present in the list below
Quantifier: + Between one and unlimited times, as many times as possible, giving back as needed [greedy]
s match any white space character [rntf ]
uFEFF matches the character uFEFF literally (case sensitive)
xA0 matches the character   with position 0xA0 (160 decimal or 240 octal) in the character set
2nd Alternative: [suFEFFxA0]+$
[suFEFFxA0]+ match a single character present in the list below
Quantifier: + Between one and unlimited times, as many times as possible, giving back as needed [greedy]
s match any white space character [rntf ]
uFEFF matches the character uFEFF literally (case sensitive)
xA0 matches the character   with position 0xA0 (160 decimal or 240 octal) in the character set
$ assert position at end of the string
g modifier: global. All matches (don't return on first match)

上面的描述使REGEX非常容易理解，但仍然考虑实际实现，一些事情没有意义，即

uFEFF为什么一个字符会有这个字符，它和空白有什么关系?xA0到底是什么?

谁能解释一下?你不必给出最详细的答案，简短的回答就可以了。

Answer 1

0xFEFF被称为ZERO WIDTH NO-BREAK SPACE，并且可能不会在某些浏览器上单独使用s。0x00A0也一样，没有空格

关于s在ECMA 262 (Javascript的标准)中捕获的更多细节，请参阅本文档。根据该规范，jQuery过于谨慎，因为有问题的字符已经包含在内。