How to remove backslash escaping from a javascript var?

Question

I have this var

var x = "<div class=\\\"abcdef\\\">"; 

Which is

<div class=\"abcdef\"> 

But I need

<div class="abcdef"> 

How can I "unescape" this var to remove all escaping characters?

Answer 1

You can replace a backslash followed by a quote with just a quote via a regular expression and the String#replace function:

var x = "<div class=\\\"abcdef\\\">";  x = x.replace(/\\"/g, '"');  document.body.appendChild(    document.createTextNode("After: " + x)  );

Note that the regex just looks for one backslash; there are two in the literal because you have to escape backslashes in regular expression literals with a backslash (just like in a string literal).

The g at the end of the regex tells replace to work throughout the string ("global"); otherwise, it would replace only the first match.

Answer 2

You can use JSON.parse to unescape slashes:

function unescapeSlashes(str) {   // add another escaped slash if the string ends with an odd   // number of escaped slashes which will crash JSON.parse   let parsedStr = str.replace(/(^|[^\\])(\\\\)*\\$/, "$&\\");    // escape unescaped double quotes to prevent error with   // added double quotes in json string   parsedStr = parsedStr.replace(/(^|[^\\])((\\\\)*")/g, "$1\\$2");    try {     parsedStr = JSON.parse(`"${parsedStr}"`);   } catch(e) {     return str;   }   return parsedStr ; }