Code change:
Describe your problem and how to reproduce it: First Issue: The Basic solution uses call() function but doesn't include any reference to it. Second Issue: The Basic solution doesn't work when you use it as a solution for the challenge. You get the following error on the beta site: I guess setting to fixes this issue. Add a Link to the page with the problem: Tell us about your browser and operating system: Browser Name: Mozilla Firefox Browser Version: 66.0.5 Operating System: Windows 10 One more thing. The error generated on the old site is helpful whereas the one on the new site isn't. Probably something to look at.
That is a valid point regarding the error message, but that is a different issue related to how the challenge tests are ran. I have gone ahead and created a PR () to address the solution in the Guide, but the last issue you mentioned will have to be discussed in a separate issue (feel free to create it if you have the time). I could not find any outstanding issues regarding why this does not show the error "assignment to undeclared variable x" which does show in the actual browser console. Are errors like this being suppressed on showing in the fake console for any reason?

Related discussion:
text: #### Relevant Links <del> *   <a href='http://forum.freecodecamp.com/t/javascript-array-prototype-map/14294' target='_blank' rel='nofollow'>Array.prototype.map</a> *   <a href='http://forum.freecodecamp.com/t/javascript-string-prototype-split/15944' target='_blank' rel='nofollow'>String.prototype.split</a> *   <a href='http://forum.freecodecamp.com/t/javascript-array-prototype-join/14292' target='_blank' rel='nofollow'>Array.prototype.join</a> </del> <ins> *   <a href='https://forum.freecodecamp.com/t/javascript-array-prototype-map/14294' target='_blank' rel='nofollow'>Array.prototype.map</a> *   <a href='https://forum.freecodecamp.com/t/javascript-string-prototype-split/15944' target='_blank' rel='nofollow'>String.prototype.split</a> *   <a href='https://forum.freecodecamp.com/t/javascript-array-prototype-join/14292' target='_blank' rel='nofollow'>Array.prototype.join</a> </ins> ## ![:sunflower:](https://forum.freecodecamp.com/images/emoji/emoji_one/sunflower.png?v=3 ":sunflower:") Intermediate Code Solution: ```javascript <del> // Solution with Regular expression and Array of ASCII character codes function rot13(str) { var rotCharArray = []; var regEx = /[A-Z]/ ; str = str.split(""); for (var x in str) { if (regEx.test(str[x])) { // A more general approach // possible because of modular arithmetic // and cyclic nature of rot13 transform rotCharArray.push((str[x].charCodeAt() - 65 + 13) % 26 + 65); } else { rotCharArray.push(str[x].charCodeAt()); } } str = String.fromCharCode.apply(String, rotCharArray); return str; </del> <ins> // Solution with Regular expression and Array of ASCII character codes function rot13(str) { var rotCharArray = []; var regEx = /[A-Z]/; str = str.split(""); for (var x in str) { if (regEx.test(str[x])) { // A more general approach // possible because of modular arithmetic // and cyclic nature of rot13 transform rotCharArray.push((str[x].charCodeAt() - 65 + 13) % 26 + 65); } else { rotCharArray.push(str[x].charCodeAt()); </ins> } <ins> } str = String.fromCharCode.apply(String, rotCharArray); return str; } </ins> <del> // Change the inputs below to test rot13("LBH QVQ VG!"); </del> <ins> // Change the inputs below to test rot13("LBH QVQ VG!"); </ins> ``` ### Code Explanation: