javascript replace（）不替换包含文字\r\\\<br/>字符串的文本 [英] javascript replace() not replacing text containing literal \r\n strings

问题描述

  value = value.replace（/ [\r\\\
] * / g，）; 
  

但是当代码实际上包含\r\\\
文本时，影响我的内容中的r和n？我试过这个代码：

  value = value.replace（/ [\\\\\
] + / g，）; 
  

在这一段文字上：

  {client：{werdfasreasfsd：asdfRasdfas\rr\\\
MCwwDQYJKoZIhvcNAQEBBQADGw ...... 
  

我结束了这一点：

  {cliet：{wedfaseasfsd ：asdfRasdfasMCwwDQYJKoZIhvcNAQEBBQADGw ...... 
  

旁注：它留下大写版本的R和N单独，因为我没有包括/ i标志在这个结束，这是确定在这种情况。

我该怎么做只是删除\

解决方案

如果你想匹配文字 \r 和文字 \\\
然后您应该使用以下内容：

  value = value.replace（/（?: \\ [rn]）+ / g，）; 
  

您可能会认为匹配的文字 \r 和 \\\
与 [\\\\\\
] 是正确的方式它有点混乱，但它不会工作，这里是为什么：

请记住，在字符类中，每个单个字符表示单个字母或符号，它不代表一个字符序列，它只是一个设置的字符。

所以角色类 [ \\\\\\
] 实际匹配文字字符 \ ， r 和 n 作为单独的字母而不是序列。

编辑：如果要替换所有回车符 \r ，换行符 \\\
还有文字 \r 和'\\\
`，则可以使用：

  value = value。替换（/（？：\\ [rn] | [\r\\\
] +）+ / g，）; 
  

关于（？：）这意味着因为默认情况下，当您将某些东西放入通常的组（）中时，它会被捕获到一个编号的变量中，您可以在正则表达式中的其他位置使用它，或者后者在匹配数组中。

（？：）阻止捕获该值并导致比（），有关详细信息，请参阅本文。

Using this bit of code trims out hidden characters like carriage returns and linefeeds with nothing using javascript just fine:

value = value.replace(/[\r\n]*/g, "");

but when the code actually contains \r\n text what do I do to trim it without affecting r's and n's in my content? I've tried this code:

value = value.replace(/[\\r\\n]+/g, "");

on this bit of text:

{"client":{"werdfasreasfsd":"asdfRasdfas\r\nMCwwDQYJKoZIhvcNAQEBBQADGw......

I end up with this:

{"cliet":{"wedfaseasfsd":"asdfRasdfasMCwwDQYJKoZIhvcNAQEBBQADGw......

Side note: It leaves the upper case versions of R and N alone because I didn't include the /i flag at the end and thats ok in this case.

What do I do to just remove \r\n text found in the string?

解决方案

If you want to match literal \r and literal \n then you should use the following:

value = value.replace(/(?:\\[rn])+/g, "");

You might think that matching literal \r and \n with [\\r\\n] is the right way to do it and it is a bit confusing but it won't work and here is why:

Remember that in character classes, each single character represents a single letter or symbol, it doesn't represent a sequence of characters, it is just a set of characters.

So the character class [\\r\\n] actually matches the literal characters \, r and n as separate letters and not as sequences.

Edit: If you want to replace all carriage returns \r, newlines \n and also literal \r and '\n` then you could use:

value = value.replace(/(?:\\[rn]|[\r\n]+)+/g, "");

About (?:) it means a non-capturing group, because by default when you put something into a usual group () then it gets captured into a numbered variable that you can use elsewhere inside the regular expression itself, or latter in the matches array.

(?:) prevents capturing the value and causes less overhead than (), for more info see this article.

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