正则表达式获取大括号之间的字符串 [英] Regex to get string between curly braces

问题描述

不幸的是，尽管在我记得的很多年里，我每年至少尝试学习一次正则表达式，但我总是忘记，因为我很少使用它们.今年我的新年决心是不再尝试学习正则表达式 - 所以今年为了让我免于流泪，我将它交给 Stack Overflow.(去年圣诞节混音).

我想以这种格式传入一个字符串{getThis}，然后返回字符串getThis.任何人都可以帮助我坚持我的新年决心吗?

<小时>

Stack Overflow 相关问题:

• 如何变成常规引号(即 ', ")转换成 LaTeX/TeX 引号(即`', ``'')
• 正则表达式: 提取字符串中两个标签之间的子字符串
• 正则表达式替换字符串中的所有 ，但没有 [code] [/code] 标签内的那些

解决方案

如果你的字符串总是采用那种格式，那么正则表达式就显得有些过分了:

<预><代码>>>>var g='{getThis}';>>>g.substring(1,g.length-1)得到这个"

substring(1 表示开始一个字符 (刚好经过第一个 {) 和 ,g.length-1) 表示取字符直到(但不包括)字符串长度减一处的字符.这是有效的，因为位置是从零开始的，即 g.length-1 是最后一个位置.

对于原始海报以外的读者:如果必须是一个正则表达式，请使用 /{([^}]*)}/ 如果你想允许空字符串，或者 /{([^}]+)}/ 如果您只想在大括号之间至少有一个字符时匹配.细分:

• /:开始正则表达式模式
  • {:文字花括号
    • (:开始捕获
      • [:开始定义一类要捕获的字符
        • ^}:除了}之外的任何东西"
      • ]:好的，这就是我们的整个类定义
      • *:匹配我们刚刚定义的那个类的任意数量的字符
    • ):完成捕获
  • }:文字花括号必须紧跟我们捕获的内容
• /:结束正则表达式

Unfortunately, despite having tried to learn regex at least one time a year for as many years as I can remember, I always forget as I use them so infrequently. This year my new year's resolution is to not try and learn regex again - So this year to save me from tears I'll give it to Stack Overflow. (Last Christmas remix).

I want to pass in a string in this format {getThis}, and be returned the string getThis. Could anyone be of assistance in helping to stick to my new year's resolution?

---

Related questions on Stack Overflow:

• How can one turn regular quotes (i.e. ', ") into LaTeX/TeX quotes (i.e. `', ``'')
• Regex: To pull out a sub-string between two tags in a string
• Regex to replace all in a String, but no those inside [code] [/code] tag

解决方案

If your string will always be of that format, a regex is overkill:

>>> var g='{getThis}';
>>> g.substring(1,g.length-1)
"getThis"

substring(1 means to start one character in (just past the first {) and ,g.length-1) means to take characters until (but not including) the character at the string length minus one. This works because the position is zero-based, i.e. g.length-1 is the last position.

For readers other than the original poster: If it has to be a regex, use /{([^}]*)}/ if you want to allow empty strings, or /{([^}]+)}/ if you want to only match when there is at least one character between the curly braces. Breakdown:

• /: start the regex pattern
  • {: a literal curly brace
    • (: start capturing
      • [: start defining a class of characters to capture
        • ^}: "anything other than }"
      • ]: OK, that's our whole class definition
      • *: any number of characters matching that class we just defined
    • ): done capturing
  • }: a literal curly brace must immediately follow what we captured
• /: end the regex pattern

这篇关于正则表达式获取大括号之间的字符串的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！