Javascript \x escapes within a mixed string

Question

I have a string that I got by using Ajax to load a preview of a web page. The title comes out like this:

You Can\xe2\x80\x99t Handle the Truth About Facebook Ads, New Harvard Study Shows

I need to replace those escape codes with human readable text. I have tried String.fromCharCode(), but that doesn't return anything in the case of a mixed string, only if you send it character codes only.

Is there a function I can use to fix this string?

Answer 1

Here's one way to do it:

const str_orig = 'You Can\\xe2\\x80\\x99t Handle the Truth About Facebook Ads, New Harvard Study Shows';

console.log("Before: " + str_orig);

const str_new = str_orig.replace(
    /(?:\\x[\da-fA-F]{2})+/g,
    m => decodeURIComponent(m.replace(/\\x/g, '%'))
);

console.log("After: " + str_new);

The idea is to replace \x by % in the string (which produces a URL encoded string), then apply decodeURIComponent, which handles UTF-8 decoding for us, turning %e2%80%99 into a single character: ’ (U+2019, RIGHT SINGLE QUOTATION MARK).