in the following test cases:

scramble_words('-dcba') == '-dbca'
as first char is "-" and last "a", shouldn't return value be "-bcda"?

scramble_words('dcba.') == 'dbca.'
as first char is "d" and last ".", shouldn't the return value be "dabc."?

Since the first and last characters remain in original place for each word. Thanks for any clarifiaction.

It doesn't say what to return if the array input is empty. I guess you return a []

Your problem is in line 3 of your code:

Note: no empty arrays will be given.

But you're generating an empty array.

And then there is another problem:

If there is a tie for most frequent number, return the largest number among them.

Your code returns the first value, not the largest one.

cool. I'll have alook

The problem is when you populate clean_str

I've renamed the function, there was a typo in its name, change it to pangram and click reset.

p panagram?("The quick brown fox jumps over the lazy dog") == true

It has both T and t, your code is still not case insensitive.

Changed the error messages, but your code is wrong, it's not case insensitive.

Thanks for clearing this up. Strings' lengths aren't necessarily the same.

That needs Ruby >= 2.7

What's wrong with array.tally?