Why not just use the string to pass the phone number as a property?

Hi!

I don't know if this answers your question adequately (since I'm not sure the exact course/video/challenge), but I'll give my $0.02, as they say.

Setters and getters are cool because they can allow you to do more with a property than just store a variable.

They can allow you to do transformations, such a concatenation or changing to uppercase or lowercase or use math functions on the incoming/outgoing data.

You can also do validation, to make sure the data is appropriate and in the right format, etc., such as turning numbers into strings and vice-versa.

And in the case of phone numbers, you can use something like RegEx to make sure it's a valid phone number and not, say, an email address.

Something like this:

function phonenumber(inputtxt) {
  var phoneno = /^\(?([0-9]{3})\)?[-. ]?([0-9]{3})[-. ]?([0-9]{4})$/;
  if(inputtxt.value.match(phoneno)) {
    return true;
  }
  else {
    alert("Not a valid phone number");
    return false;
  }
}

(Of course, that's just a function, but you could use similar code in your setter/getter.)

Does that make sense?

More info:

https://teamtreehouse.com/library/practice-getters-and-setters-in-javascript

I hope that helps.

Stay safe and happy coding!