JavaScript RegExp对象 [英] JavaScript RegExp objects

问题描述

我尝试用JavaScript编写一个简单的Markdown解析器。因此，我想检查 [link content] [link id] 语法。我使用以下代码：

I try to write a simple Markdown parser in JavaScript. Therefore I want to check for the [link content][link id] syntax. I use the following code:

data = data.replace( /\[(.*?)\][ ]*\[([0-9]+)\]/g, '<a href="$2">$1</a>' );

它运行良好，但现在我想用RegExp对象执行此操作。所以我设置了以下代码：

It works well, but now I want to do this with a RegExp object. So I set up the following bit of code:

var r = new RegExp( '\[(.*?)\][ ]*\[([0-9]+)\]', 'g' );
data = data.replace( r, '<a href="$2">$1</a>' );

但它不起作用。它甚至说我的正则表达式（自第一个例子以来工作得很好）无效：

But it doesn't work. It even says that my regular expression (which works since the first example does a good job) is invalid:

无法比拟的正则表达式

unmatched ) in regular expression

我认为它必须与我不知道的一些RegExp-object特性有关。
我做错了什么以及如何解决问题？

I think it must have to do with some RegExp-object peculiarities I am not aware of. What am I doing wrong and how can the problem be solved?

推荐答案

因为RegExp构造函数的第一个参数是一个字符串，而不是模式文字，你必须转义反斜杠，因为你需要模式中的文字反斜杠：

Because the first argument of the RegExp constructor is a string, not a pattern literal, you have to escape the backslashes, since you want literal backslashes in the pattern:

var r = new RegExp( '\\[(.*?)\\][ ]*\\[([0-9]+)\\]', 'g' );

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