RegEx Not Recognizing Invalid Email

Question

I am trying to validate an email address for a form element. I am familiar with regular expressions so I believe that part is correct, but I want it to display an alert when the email entered is invalid. My problem is that the form submits even when I enter an invalid email address instead of popping up the alert window.

RegEx function in javascript:

function validateEmail()
            {
                var myEmailRegEx = /\w+@\w+\.[a-z]|[A-Z]|\d|\.|-{2,}/

                if(myEmailRegEx.test(document.getElementById("EmailAddress")))
                {
                    return true;
                }
                else
                {
                    alert("That is not a valid email address");
                    return false;
                }
            }

form HTML:

<input type="text" name="Email" id="EmailAddress" size="50" />
        <br />
        <input type="submit" value="Submit Email" onClick="validateEmail();" />

Works On Mine · Accepted Answer · 2014-03-17 19:49:40Z

1

Just for the sake of clarity, the problem with what you were doing was that you were giving an object to the regex for testing, which always returns true(weird though). With the .value we get the string that the field holds and then test the regex against it.

you should use,

var myEmailRegEx = new RegExp("/\w+@\w+\.[a-z]|[A-Z]|\d|\.|-{2,}")
myEmailRegEx.test(document.getElementById("EmailAddress").value)

Suppose that email address is present in a form with id = "my_form". To prevent the default submission of that form, you would use

$("#my_form").preventDefault();

if the email turns out to be true, you could then submit the form.

if(myEmailRegEx.test(document.getElementById("EmailAddress").value)){
   document.getElementById("mu_form").submit();
}

that should be it. I hope you have an idea where to plug in these code snippets :-)

edited Mar 17, 2014 at 19:49

answered Mar 17, 2014 at 19:36

Works On Mine

1,1311 gold badge8 silver badges20 bronze badges

Sign up to request clarification or add additional context in comments.

3 Comments

user2433662 Over a year ago

ok. now the if statement works. thanks! but when the user clicks "ok" on the alert window, the form submits anyway. is there a way to cancel the submission if the validation fails?

Works On Mine Over a year ago

you should use the prevent default function to prevent submission. I will just make an edit for that. BTW, could you accept my answer?

user2433662 Over a year ago

i will. it says i have to wait 5 minutes before i can accept the answer. as soon it as it allows me to I will though.

Niet the Dark Absol · Accepted Answer · 2014-03-17 19:45:51Z

1

Could just do:

<input type="email" />

and be done with it.

answered Mar 17, 2014 at 19:45

Niet the Dark Absol

326k86 gold badges480 silver badges604 bronze badges

Comments

whyceewhite · Accepted Answer · 2014-03-17 19:38:30Z

0

Try using an onchange event on the input field contain the email. For example:

<input type="text" name="Email" id="EmailAddress" size="50" onchange="validateEmail();" />
<br />
<input type="submit" value="Submit Email"/>

The above approach will call your validateEmail function whenever the value changes in that field.

answered Mar 17, 2014 at 19:38

whyceewhite

6,4457 gold badges47 silver badges52 bronze badges

Comments

Nick Humrich · Accepted Answer · 2014-03-17 19:44:35Z

0

While this doesn’t directly answer your question, it should be noted that your regex returns a lot of false negatives. For example, and email address with a . in the address, such as my personal email address, [email protected]

A good starting place is to start here

I will copy the "basic" email regex below for convenience.

^[A-Z0-9._%+-]+@[A-Z0-9.-]+\.[A-Z]{2,4}$

answered Mar 17, 2014 at 19:44

Nick Humrich

15.8k10 gold badges67 silver badges88 bronze badges

Collectives™ on Stack Overflow

RegEx Not Recognizing Invalid Email

4 Answers 4

3 Comments

Comments

Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

4 Answers 4

3 Comments

Comments

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related