正则表达式删除Java脚本中的空格，空白行和最后一个换行符 [英] Regex to remove white spaces, blank lines and final line break in Javascript

问题描述

好的，我在使用正则表达式时遇到了麻烦.

Ok guys, I'm having a hard time with regex..

这就是我需要的...获取文本文件，删除这些行的开头和结尾的所有空白行和空格，要删除的空白行在文件末尾还包括一个空行(全文末尾的\ n)

Here's what I need... get a text file, remove all blank lines and white spaces in the beginning and end of these lines, the blank lines to be removed also include a possible empty line at the end of the file (a \n in the end of the whole text)

所以我的脚本是:

quotes.replace(/^\s*[\r\n]/gm, "");

替换效果很好，但是每行末尾留了一个空格，并且不会删除最后的换行符.

This replaces fairly well, but leaves one white space at the end of each line and doesn't remove the final line break.

所以我想使用这样的东西:

So I thought using something like this:

quotes.replace(/^\s*[\r\n]/gm, "").replace(/^\n$/, "");

第二个替换"会从整个字符串中删除最后一个\ n，如果存在..但不起作用.

The second "replace" would remove a final \n from the whole string if present.. but it doesn't work..

所以我尝试了这个:

quotes.replace(/^\s*|\s*$|\n\n+/gm, "")

删除换行符，但是在中间出现换行符时加入一些行:

Which removes line breaks but joins some lines when there is a line break in the middle:

这样
1
2
3

4

so that
1
2
3

4

将返回以下行:

["1"，"2"，"34"]

["1", "2", "34"]

你们能帮我吗?

推荐答案

由于听起来您必须在单个正则表达式中完成所有操作，因此请尝试以下操作:

Since it sounds like you have to do this all in a single regex, try this:

quotes.replace(/^(?=\n)$|^\s*|\s*$|\n\n+/gm,"")

我们正在做的工作是创建一个不捕获任何内容的组，但阻止换行本身被占用.

What we are doing is creating a group that captures nothing, but prevents a newline by itself from getting consumed.

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