简单的正则表达式问题，我只是无法弄清楚

I have quite a simple problem, I need to parse through this string:

我有一个非常简单的问题，我需要解析这个字符串：

"user_id" => "BXoVWYg-T_QS"

And grab only the BXoVWYg-T_QS

并且只抓住BXoVWYg-T_QS

I have used regex thus far to grab that much from a much larger string, but I can't figure out how to get it down to just the contents of the user_id string

到目前为止，我已经使用正则表达式来从一个更大的字符串中获取那么多，但是我无法弄清楚如何将其归结为user_id字符串的内容

This is the regex I have so far:

这是我到目前为止的正则表达式：

"user_id" => ".*"

Please help!

请帮忙！

Update I have a string of html that I am trying to parse through for an iPhone app in objective-c. If I can just get the regex syntax down, my problems will be solved

更新我有一串html，我试图解析Objective-c中的iPhone应用程序。如果我能够正确地获得正则表达式语法，我的问题将得到解决

3 个解决方案

#1

"user_id" => "([^"]*)"

#2

You need to indicate your capture using parens like this:

你需要使用这样的parens表示你的捕获：

"user_id" => "(.*)"

You can then locate that match. Are you using JavaScript, Perl, C#, ???

然后，您可以找到该匹配项。你使用的是JavaScript，Perl，C＃，???

#3

The problem is that .* is greedy -- so it grabs everything up to the last available " in your line / string (depending on the mode you are using).

问题是。*是贪婪的 - 所以它抓住你的行/字符串中的最后一个可用的东西（取决于你使用的模式）。

What you need is to either:

你需要的是：

A) Make the regex non-greedy. .*? will do that in some platforms.
B) Specifically exclude " from the list of characters you'd like to match: "user_id" => "([^"]*)" is what you'll want then.

A）使正则表达式不贪婪。。*？会在某些平台上做到这一点。 B）明确排除“你想要匹配的字符列表：”user_id“=>”（[^“] *）”就是你想要的。

#1

"user_id" => "([^"]*)"

#2