How to remove backslash escaping from a javascript var?

Question

I have this var

var x = \"
\";

Which is

Answer 1

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(/(^|[^\\])(\\\\)*\\$/, "$&\\");

  try {
    parsedStr = JSON.parse(`"${parsedStr}"`);
  } catch(e) {
    return str;
  }
  return parsedStr ;
}