Stuck on Mutation challenge

I have been stuck on this challenge for over a day. I am unable to get all “green checks” and not sure what to do. Please help:

'function mutation(arr) {
for (i = 0; i < arr.length; i++){
res= arr.sort(arr[i]);

if(res.indexOf(i) !== -1);
}
return false;

}
mutation([“hello”, “hey”]);’

Hey, have a look at your code. What does the if statement do? Also you only return false, no matter what.

This if statement is to compare if the characters in the second argument exists in the first argument. If not it should return false.

I originally had the if statement as follows:

if(res.indexOf(i) !== if(res.indexOf(0));

but it did not work either even though it returned false

But the if statement doesn’t do anything. if(res.indexOf(i) !== -1); It just checks it and goes on. An if statement should be as follows:

if(<check>){ 
  // do something 
}

So that would be:

if(res.indexOf(i) !== -1){
  return false;
}else{
  return true; 
}