Swift - 正则表达式匹配括号

I am trying to use regex to search through a string: "K1B92 (D) [56.094]" and I want to grab the "(D)" including the parentheses surrounding the "D". I am having trouble finding the correct expression to match the actual parentheses as simply putting parentheses will take it as a block and trying to escape the parentheses with "\" making it think its an expression to be evaluated. I also tried escaping "\(" with "\\(" as so: "\\([ABCD])\\)" but without luck. This is the code I have been using:

我正在尝试使用正则表达式搜索字符串：“K1B92（D）[56.094]”并且我想抓住“（D）”，包括围绕“D”的括号。我无法找到正确的表达式来匹配实际的括号，因为简单地将括号放在一个块中并试图用“\”来转义括号，使它认为它是一个要评估的表达式。我也尝试转义“\（”与“\\（”如此：“\\（[ABCD]）\\）”，但没有运气。这是我一直在使用的代码：

let str = "K1B92 (D) [56.094]"

let regex = NSRegularExpression(pattern: "\\b\\([ABCD])\\)\\b", options: NSRegularExpressionOptions.CaseInsensitive, error: nil)

let match = regex?.firstMatchInString(str, options: NSMatchingOptions.WithoutAnchoringBounds, range: NSMakeRange(0, count(str)))

let strRange = match?.range
let start = strRange?.location
let length = strRange?.length

let subStr = str.substringWithRange(Range<String.Index>(start: advance(str.startIndex, start!), end: advance(str.startIndex, start! + length!)))

// "\\b\([ABCD])\)\\b" returns range only for the letter "D" without parentheses.
// "\\b\\([ABCD])\\)\\b" returns nil

Can direct me towards the correct expression please? Thank you very much.

能引导我走向正确的表达吗？非常感谢你。

2 个解决方案

#1

~~The \\([ABCD])\\) part is OK,~~ Correction: As @vacawama correctly said in his answer, the parentheses do not match here. \\([ABCD]\\) matches one of the letters A-D enclosed in parentheses.

\\（[ABCD]）\\）部分没问题，更正：正如@vacawama在答案中正确说的那样，括号在这里不匹配。 \\（[ABCD] \\）匹配括号中的一个字母A-D。

The other problem is that there is no word boundary (\b pattern) between a space and a parenthesis.

另一个问题是空格和括号之间没有单词边界（\ b模式）。

So you could either (depending on your needs), just remove the \b patterns, or replace them by \s for white space:

所以您可以（根据您的需要），只需删除\ b模式，或者用\ s替换它们以获取空白：

let regex = NSRegularExpression(pattern: "\\s\\([ABCD]\\)\\s", ...

But since the matched string should not include the space you need a capture group:

但由于匹配的字符串不应包含空间，因此需要捕获组：

let regex = NSRegularExpression(pattern: "\\s(\\([ABCD]\\))\\s", ...
// ...
let strRange = match?.rangeAtIndex(1)

#2

The regular expression you need is "\\([ABCD]\\)". You need the double escape \\ before both open paren ( and close paren ).

您需要的正则表达式是“\\（[ABCD] \\）”。在打开paren（和关闭paren）之前你需要双重转义\\。

#1