Why do I only get 94% completed?

I just finished Basic Algorithm Scripting: Mutations and I only get 94% completed. Is this a new thing? I can submit the challenge and move on, but I wonder why the score is 94% when all the test are checked?

Here is my code, I know it is not the best and most compact solution, but it does get the job done. any thoughts on my solution?

function mutation(arr) {
var firstString = arr[0].toLowerCase();
var secondString = arr[1].toLowerCase();
var result = ;
var arr;

/*check whether the individuel letter of secondstring exist in firststring */
for(var i = 0; i < secondString.length; i++) {
/*if true push true to result array, else push false */
if(firstString.includes(secondString[i])) {
} else {
/*if result array has a false in it, return arr as false else return as true */
if(result.includes(“false”)) {
arr = false;
} else {
arr = true;

return arr;

mutation([“hello”, “hey”]);

The percentage shown after you finish a challenge is a progress meter for the entire section, not a grade on your solution. There is one more challenge in that section, Chunky Monkey. Once you complete that last one your progress meter should go up to 100%.


Okay, I feel dumb now :slight_smile: well thats what I get for being away for some months :sweat_smile:

Thanks for the explanation :ok_hand:

No problem! Better to ask and be sure it’s done right than half-@ss it when something could be better, no?

Could not agree more, the best way to learn is to try and do it right. Then all the bad habits can come afterwards.
Have a nice evening, or what time it may be where you are at :slight_smile: