Mutations - dont know how to compare words

1 
function mutation(arr) { 

for(var i = 0; i < arr.length; i ++) { 
  arr[i] = arr[i].toLowerCase().split('');  
  if (arr[0].indexOf(arr[0]) == arr[0].indexOf(arr[1])) {  
    return true;
  } else {
    return false;
  }  
}
  return arr;
}

mutation(["Mary", "Army"]);

any idea on how can i compare these two word s/ or what am i doing wrong? thank you

2

I get true when I run the following with your code.

mutation(["Mary", "Army"]);

Your code is correctly returning true, because all of the letters in the second argument “Army” are in the first argument “Mary”.

Which test(s) are you failing?

3

Im failing every tests that are supposed to show “false”

4

Actually, I figured it out. Your algorithm is going the wrong direction.

First of all, not sure why you are looping through the array when you know it will always have only 2 items. You can refer to those as arr[0] and arr[1]. Once you realize that, you only need to create a loop which loops through each letter of arr[1] and see if that letter is somewhere in arr[0]. You are on the right track using indexOf, but you only need to be using it on arr[0] and not on both.

Whenever you are unsure what a specific line of code is doing, console.log() is your friend. I was going to try to explain why your code shows true for everything, but it was complicated and I felt it was better to point a few mistakes out and get you started in the right direction. If you need more help or hints, please feel free to ask.

5

Thank you for your reply. My main reason for loop was that i wanted to lowercase all words as just using .toLowerCase(). wasnt working for me .

6

You will still have a for…loop but you don’t have to loop through an array. Also, I find it easier to work with variables names instead of things like arr[0] or arr[1]. If you want to convert the words to lower case you must assign them to a new variable because strings themselves are immutable.

For example, it might help to do something like this at the beginning of your function:

  var lettersToCheck = arr[0].toLowerCase();
  var lettersToFind = arr[1].toLowerCase();

Now you have lower case versions of each word. The best part is, you no longer have to refer to arr[0] or arr[1] or remember which one is supposed to be checking which, because your variable names make it clear.

1 Like
7

ok got it … thank you :slight_smile:

8

I cleaned up your code.
You need to use triple backticks to post code to the forum.
See this post for details.

9 
function mutation(arr) {
  
  var lettersToCheck = arr[0].toLowerCase();
  var lettersToFind = arr[1].toLowerCase();

for (var i = 0; i < lettersToFind.length; i ++) {
  

  
  if (lettersToCheck.indexOf(lettersToFind[i]) >= 0) {
    
        return true;
      } else {
        return false;
      } 
} 
  return arr;
}

mutation(["hello", "hey"]);

it doesnt return false in case [“hello”, “hey”] but other variants passes … any hint about what im doing wrong ?

10

Your code checks only the first letter and after that it returns.

11

You’re trying to see if each index of arr[1] matches an index of arr[0]. Hint: nested loops, one for each item.

I like your idea of lower-casing both items. I used RegExp to ignore case in my solution.

12