我需要在正则表达式中逃脱破折号吗？

问题描述

我正在尝试理解短划线字符 - 需要使用正则表达式中的反斜杠进行转义吗？

I'm trying to understand dash character - needs to escape using backslash in regex?

考虑这一点：

var url     = '/user/1234-username';
var pattern = /\/(\d+)\-/;
var match   = pattern.exec(url);
var id      = match[1]; // 1234

正如您在上面的正则表达式中所看到的，我正在尝试提取id的数量来自网址。我还使用反斜杠 \ 在我的正则表达式中转义 - 字符。但是当我删除那个反斜杠时，仍然很好....换句话说，这两个都很好：

As you see in the above regex, I'm trying to extract the number of id from the url. Also I escaped - character in my regex using backslash \. But when I remove that backslash, still all fine ....! In other word, both of these are fine:

• ）。

  You only need to escape the dash character if it could otherwise be interpreted as a range indicator (which can be the case inside a character class).

  /-/        # matches "-"
  /[a-z]/    # matches any letter in the range between ASCII a and ASCII z
  /[a\-z]/   # matches "a", "-" or "z"
  /[a-]/     # matches "a" or "-"
  /[-z]/     # matches "-" or "z"
  

  这篇关于我需要在正则表达式中逃脱破折号吗？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！