带有转义斜杠的JavaScript正则表达式不会替换 [英] JavaScript regex with escaped slashes does not replace

问题描述

将它们放入正则表达式时是否必须转义斜杠？

Do i have to escape slashes when putting them into regular expression?

myString = '/courses/test/user';
myString.replace(/\/courses\/([^\/]*)\/.*/, "$1");
document.write(myString);

它不打印test，而是打印整个源字符串。

Instead of printing "test", it prints the whole source string.

参见此演示：

http://jsbin.com/esaro3/2/edit

推荐答案

你的正则表达式是完美的，是的，你必须转义斜杠，因为JavaScript使用斜杠来表示正则表达式。

Your regex is perfect, and yes, you must escape slashes since JavaScript uses the slashes to indicate regexes.

然而，问题是JavaScript的替换方法不执行就地替换。也就是说，它实际上并没有改变字符串 - 它只是给你替换的结果。

However, the problem is that JavaScript's replace method does not perform an in-place replace. That is, it does not actually change the string -- it just gives you the result of the replace.

试试这个：

myString = '/courses/test/user';
myString = myString.replace(/\/courses\/([^\/]*)\/.*/, "$1");
document.write(myString);

这将 myString 设置为替换值。

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