Trim() not working properly?

Question

I'm building out a function to allow users to change their email address and if they accidentally put in a whitespace before or after, I need to trim it so the regex doesn't complain. It doesn't seem to work in the place I have it (the string remains exactly the same) but I'm not sure why. This is in my controller:

public ActionResult ChangeEmail(ChangeEmailVM vm)
        {
            try
            {
                if (UserManager.EmailAvail(new EmailRequest
                {
                    Email = vm.EmailAddress.Trim()
                }))
                else//...etc etc

I was thinking I'd possibly need to put .trim() in the getter or setter of the email address but I'm not sure of the proper syntax.

Please elaborate about 'not working properly'. What do you expect it to do, and what is it doing? — Rob, Nov 25 '15 at 23:07
Trim will only remove trailing or leading whitespace. If you want to remove all whitespace, use replace. — JD Davis, Nov 25 '15 at 23:08
This might help http://stackoverflow.com/questions/6219454/efficient-way-to-remove-all-whitespace-from-string — myselfmiqdad, Nov 25 '15 at 23:10
It doesn't affect the input at all. So if the user enters " xyz@test.com " (with whitespace before and after), it will still leave all of the extra whitespaces — xyzcode, Nov 25 '15 at 23:24
Trim doesn't mutate the string. It returns a new string that has been trimmed. You've only passed the trimmed string into `EmailAvailForReg`. `UpdateEmail` is not going to have the trimmed string because the `EmailAddress` property on `viewModel` wasn't changed. — Mike Zboray, Nov 25 '15 at 23:27

David · Accepted Answer · 2020-12-14T14:40:14.643

Keep in mind that string is read only - you cannot change the value by calling anything on it, and instead these methods return new values with the desired changes, including .Trim; if you wish to change viewModel.EmailAddress you should assign the result of Trim() to that same variable:

EDIT: At some point, I would like to see a .= operator, since this kind of "mutate and save" comes up surprisingly often

viewModel.EmailAddress = viewModel.EmailAddress.Trim()

Trim() not working properly?

1 Answers1