javascript - 使用正则表达式匹配一次空字符串、逗号、连字符或下划线

Question

我正在尝试找出如何匹配以下字符串:

blaOSXbla
os X bla
bla os-x
blablaOS_Xbla

一个常见的模式非常简单:/(osx|os x|os-x|os_x)/i.test(string)

任务是尽可能地减少它。所以我的下一步是 /(os)x| x|-x|_x)/i.test(string).

我也尝试过 /os(.*?)x/ 模式，但它匹配 os 和 x 之间的任意数量的符号>。如何让它匹配零个或一个符号？

Answer 1

您需要使用 character class :

/os[ _-]?x/i

参见 demo

With a "character class", also called "character set", you can tell the regex engine to match only one out of several characters. Simply place the characters you want to match between square brackets. If you want to match an a or an e, use [ae].

A character class matches only a single character. gr[ae]y does not match graay, graey or any such thing. The order of the characters inside a character class does not matter. The results are identical.

您需要 ? 来使匹配成为可选的。

参见 "Optional Items" :

The question mark makes the preceding token in the regular expression optional. colou?r matches both colour and color. The question mark is called a quantifier.