Backslash in Regular Expressions
JavaScript FAQ |
JavaScript Strings and RegExp FAQ
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Question: How do I match a backslash using regular expressions?
Answer: The following regular expressions will allow you to match or replace backslashes:
/\\/ // (1) matches one backslash (the 1st occurrence only)
/\\/g // (2) matches any occurrence of backslash (global search)
re1 = new RegExp("\\\\","") // same as (1), with RegExp constructor
re2 = new RegExp("\\\\","g") // same as (2), with RegExp constructor
Note that, to match a backslash verbatim, in accordance with
JavaScript regular expression syntax
you need two backslash characters in your regular expression literals such as
/\\//\\/gRegExp constructor, you have to double each of the two backslashes
in the string argument passed to the constructor, like this: "\\\\".
Here are some more examples:
// Test if str contains at least one backslash strHasBackslashes = (/\\/).test(str); // Replace any '\' in str1 with '/' and store the result in str2 str2 = str1.replace(/\\/g,"/");Below are the same examples rewritten with
RegExp constructor calls:
// Test if str contains at least one backslash
re1 = new RegExp("\\\\","")
strHasBackslashes = re1.test(str);
// Replace any '\' in str1 with '/' and store the result in str2
re2 = new RegExp("\\\\","g");
str2 = str1.replace(re2,"/");