JavaScript RegExp：匹配，但不捕获(JavaScript RegExp: match, but don't capture)

JavaScript RegExp：匹配，但不捕获(JavaScript RegExp: match, but don't capture)

SO上有一千个正则表达式问题，所以我很抱歉如果这已经被覆盖了。 我确实首先看。

鉴于以下模式：

(?:/|-)[0-9]{2}$

以下字符串：

str1 = '65/65/65' str2 = '65/65/6565'

比赛是：

str1 = '/65' // expected '65' str2 = '' // as I expected

我的意图是：匹配，但不包括a /或- 。 什么是正确的正则表达式来满足我的期望？

There are a thousand regular expression questions on SO, so I apologize if this is already covered. I did look first.

Given the following pattern:

(?:/|-)[0-9]{2}$

And the following strings:

str1 = '65/65/65' str2 = '65/65/6565'

The matches are:

str1 = '/65' // expected '65' str2 = '' // as I expected

My intention with ?: was to match, but not include a / or -. What is the correct regular expression to meet my expectations?

最满意答案

由于Javascript中没有可用的后视图，只需将所需的部分包装到捕获组中即可 ：

var str = '65/66/67'; if(res = str.match(/(?:\/|-)([0-9]{2})$/)) { console.log(res[1]); }

看小提琴

注意： (?:\/|-)可以用@anubhava评论的字符类 [\/-]替换。

As there's no lookbehind available in Javascript, just wrap the desired part into a capturing group:

var str = '65/66/67'; if(res = str.match(/(?:\/|-)([0-9]{2})$/)) { console.log(res[1]); }

See fiddle

Note: (?:\/|-) can be replaced with a character class [\/-] like @anubhava commented.